Page 1 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 2 OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks.
Page 3 Routing Fundamentals Packet Switching Routing Metrics Path Length Reliability Routing Delay Bandwidth Load Communication Cost Router IDs Autonomous Systems Convergence Load Balancing and Equal Cost Multipath Route Redistribution Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 4: Table Of Contents
C H A P T E R Information About IPv4 Multiple IPv4 Addresses Address Resolution Protocol ARP Caching Static and Dynamic Entries in the ARP Cache Devices that Do Not Use ARP Reverse ARP Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 5 C H A P T E R Information About OSPFv2 Hello Packet Neighbors Adjacency Designated Routers Areas Link-State Advertisements LSA Types Link Cost Flooding and LSA Group Pacing Link-State Database Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 6 Limiting the Number of Redistributed Routes 3-32 Configuring Route Summarization 3-34 Configuring Stub Route Advertisements 3-35 Modifying the Default Timers 3-36 Restarting an OSPFv2 Instance 3-39 Configuring OSPFv2 with Virtualization 3-39 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 7 Creating an EIGRP Instance 4-10 Restarting an EIGRP Instance 4-12 Shutting Down an EIGRP Instance 4-13 Configuring a Passive Interface for EIGRP 4-13 Shutting Down EIGRP on an Interface 4-13 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 8 Step 2—Determining the Order of Comparisons Step 3—Determining the Best-Path Change Suppression BGP and the Unicast RIB BGP Virtualization Licensing Requirements for Basic BGP Prerequisites for BGP Guidelines and Limitations for BGP Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) viii...
Page 9 Peer Templates Authentication Route Policies and Resetting BGP Sessions eBGP iBGP AS Confederations Route Reflector Capabilities Negotiation Route Dampening Load Sharing and Multipath Route Aggregation BGP Conditional Advertisement Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 10 6-27 Configuring Dynamic Capability 6-27 Configuring Aggregate Addresses 6-28 Configuring BGP Conditional Advertisement 6-28 Configuring Route Redistribution 6-30 Configuring Multiprotocol BGP 6-32 Tuning BGP 6-33 Configuring Virtualization 6-36 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 11 7-11 Configuring Route Redistribution 7-12 Configuring Virtualization 7-13 Tuning RIP 7-16 Verifying the RIP Configuration 7-17 Displaying RIP Statistics 7-17 Configuration Examples for RIP 7-18 Related Topics 7-18 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 12 Layer 3 Virtualization Overview of Layer 3 Virtualization VRF and Routing VRF-Lite VRF-Aware Services Reachability Filtering Combining Reachability and Filtering Licensing Requirements for VRFs Guidelines and Limitations Default Settings Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 13 Feature History for Unicast RIB and FIB 10-10 Configuring Route Policy Manager 11-1 C H A P T E R Information About Route Policy Manager 11-1 Prefix Lists 11-2 MAC Lists 11-2 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) xiii...
Page 14 Information About HSRP 12-1 HSRP Overview 12-2 HSRP for IPv4 12-3 HSRP Versions 12-4 HSRP Authentication 12-4 HSRP Messages 12-4 HSRP Load Sharing 12-4 Object Tracking and HSRP 12-5 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 15 Licensing Requirements for VRRP 13-6 Guidelines and Limitations 13-6 Default Settings 13-6 Configuring VRRP 13-7 Enabling the VRRP Feature 13-7 Configuring VRRP Groups 13-8 Configuring VRRP Priority 13-9 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 16 14-13 Related Documents 14-14 Standards 14-14 Feature History for Object Tracking 14-14 IETF RFCs A P P E N D I X BGP RFCs First-Hop Redundancy Protocols RFCs Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 17 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m IP Services RFCs OSPF RFCs RIP RFCs L O S S A R Y N D E X Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) xvii...
Page 18 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 19: Supported Switches
• Cisco Nexus 3000 Platform Switches Table 1 describes the Cisco Nexus 3000 Series switch: For more information on these switches, see the Cisco Nexus 3000 Series Hardware Installation Guide Note available at the following URL: http://www.cisco.com/en/US/products/ps9670/tsd_products_support_series_home.html Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 20 Describes how to configure the Route Policy Manager, Manager” including IP prefix lists and route maps for filtering and redistribution. Chapter 12, “Configuring HSRP” Describes how to configure the Hot Standby Routing Protocol. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 21: Document Conventions
Means reader take note. Notes contain helpful suggestions or references to material not covered in the Note manual. Means reader be careful. In this situation, you might do something that could result in equipment Caution damage or loss of data. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 22: Related Documentation
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Related Documentation Documentation for Cisco Nexus 3000 Series Switches and Cisco Nexus 2000 Series Fabric Extender is available at the following URL: http://www.cisco.com/en/US/products/ps9670/tsd_products_support_series_home.html...
Page 23: Technical References
Cisco technical documentation, at: http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html Subscribe to the What’s New in Cisco Product Documentation as an RSS feed and set content to be delivered directly to your desktop using a reader application. The RSS feeds are a free service. Cisco currently supports RSS Version 2.0.
Page 24 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 25 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m C H A P T E R Overview This chapter introduces the underlying concepts for Layer 3 unicast routing protocols in Cisco NX-OS. This chapter includes the following sections: Information About Layer 3 Unicast Routing, page 1-1 •...
Page 26 The next hop might be the ultimate destination host or another router that executes the same switching decision process. As the packet moves through the internetwork, its physical address changes, but its protocol address remains constant (see Figure 1-1). Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 27 This section includes the following metrics: Path Length, page 1-4 • Reliability, page 1-4 • Routing Delay, page 1-4 • Bandwidth, page 1-4 • Load, page 1-4 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 28 For example, the line delay for a private line might be longer than a public line, but you can send packets over your private line rather than through the public lines that cost money for usage time. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 29: Router Ids
ID. You can configure the router ID to any interface in the router system. If you do not configure the router ID, Cisco NX-OS selects the router ID based on the following criteria: Cisco NX-OS prefers loopback0 over any other interface. If loopback0 does not exist, then Cisco •...
Page 30 The number of paths used is limited by the number of entries that the routing protocol puts in the routing table. Cisco NX-OS supports up to 16 paths to a destination.
Page 31: Administrative Distance
To configure a true stub network, you should configure the distribution router to send only a default route to the remote router. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 32: Routing Algorithms
BGP is an example of an exterior gateway protocol. Routing protocols used within an autonomous system are called interior gateway protocols or intradomain protocols. EIGRP and OSPF are examples of interior gateway protocols. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 33: Distance Vector Protocols
However, link-state algorithms require more CPU power and memory than distance vector algorithms. Link-state algorithms can be more expensive to implement and support. Link-state protocols are generally more scalable than distance vector protocols. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 34: Layer 3 Virtualization
OSPF is an example of a link-state protocol. Layer 3 Virtualization Cisco NX-OS supports multiple Virtual Routing and Forwarding Instances (VRFs) and multiple routing information bases (RIBs) to support multiple address domains. Each VRF is associated with a routing information base (RIB) and this information is collected by the Forwarding Information Base (FIB). A VRF represents a Layer 3 addressing domain.
Page 35: Adjacency Manager
Multiple prefixes could share a next-hop adjacency information structure. The unicast FIB also enables and disables unicast reverse path forwarding (RPF) checks per interface. The Cisco Nexus 3000 Series supports the following two RPF modes that can be configured on each ingress interface: RPF Strict Check—Packets that do not have a verifiable source address in the routers forwarding...
Page 36: Hardware Forwarding
Software Forwarding The software forwarding path in Cisco NX-OS is used mainly to handle features that are not supported in hardware or to handle errors encountered during hardware processing. Typically, packets with IP options or packets that need fragmentation are passed to the CPU. The unicast RIB and the adjacency manager makes the forwarding decisions based on the packets that should be switched in software or terminated.
Page 37: Ipv4
The EIGRP protocol is a unicast routing protocol that has the characteristics of both distance vector and link-state routing protocols. It is an improved version of IGRP, which is a Cisco proprietary routing protocol. EIGRP relies on its neighbors to provide the routes, typical to a distance vector routing protocol.
Page 38: Layer 3 Virtualization
Chapter 9, “Configuring Layer 3 Virtualization.” Route Policy Manager The Route Policy Manager provides a route filtering capability in Cisco NX-OS. It uses route maps to filter routes distributed across various routing protocols and between different entities within a given routing protocol.
Page 39 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m A R T...
Page 40 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m...
Page 41: Configuring Ipv4
C H A P T E R Configuring IPv4 This chapter describes how to configure Internet Protocol version 4 (IPv4), which includes addressing, Address Resolution Protocol (ARP), and Internet Control Message Protocol (ICMP), on the Cisco NX-OS switch. This chapter includes the following sections: Information About IPv4, page 2-1 •...
Page 42: Multiple Ipv4 Addresses
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m The IP feature in the Cisco NX-OS system is responsible for handling IPv4 packets, as well as forwarding of IPv4 packets, which includes IPv4 unicast/multicast route lookup, reverse path forwarding (RPF) checks, and software access control list (ACL) forwarding.
Page 43: Arp Caching
The default time limit is 25 minutes but you can modify the time limit if the network has many routes that are added and deleted from the cache. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 44: Devices That Do Not Use Arp
Each server must be configured with a table of static mappings between the hardware addresses and • IP addresses. Maintenance of the IP addresses is difficult. RARP only provides IP addresses of the hosts and not subnet masks or default gateways. • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 45: Proxy Arp
Gratuitous ARP Gratuitous ARP sends a request with identical source IP address and destination IP address to detect duplicate IP addresses. Cisco NX-OS Release 5.0(3) support enabling or disabling gratuitous ARP requests or ARP cache updates. ICMP You can use ICMP to provide message packets that report errors and other information that is relevant to IP processing.
Page 46: Licensing Requirements For Ipv4
IPv4 requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 47: Configuring Ipv4
• Configuring IP Directed Broadcasts, page 2-13 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Configuring IPv4 Addressing You can assign a primary IP address for a network interface.
Page 48: Configuring Multiple Ip Addresses
You can only add secondary IP addresses after you configure primary IP addresses. SUMMARY STEPS configure terminal interface ethernet number no switchport ip address ip-address/length [secondary] (Optional) show ip interface (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 49: Configuring A Static Arp Entry
You can configure a static ARP entry on the switch to map IP addresses to MAC hardware addresses, including static multicast MAC addresses. SUMMARY STEPS configure terminal interface ethernet number no switchport ip arp ipaddr mac_addr (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 50: Configuring Proxy Arp
You can configure Proxy ARP on the switch to determine the media addresses of hosts on other networks or subnets. SUMMARY STEPS configure terminal interface ethernet number no switchport ip proxy-arp (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 2-10...
Page 51: Configuring Local Proxy Arp
Configuring Local Proxy ARP You can configure Local Proxy ARP on the switch. SUMMARY STEPS configure terminal interface ethernet number no switchport ip local-proxy-arp (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 2-11...
Page 52: Configuring Gratuitous Arp
You can configure gratuitous ARP on an interface. SUMMARY STEPS configure terminal interface ethernet number no switchport ip arp gratuitous {request | update} (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 2-12...
Page 53: Configuring Ip Directed Broadcasts
If directed broadcast is enabled for an interface, incoming IP packets whose addresses identify them as directed broadcasts intended for the subnet to which that interface is attached will be exploded as broadcasts on that subnet. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 2-13...
Page 54: Verifying The Ipv4 Configuration
192.2.1.1/16 Additional References For additional information related to implementing IP, see the following sections: Related Documents, page 2-15 • Standards, page 2-15 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 2-14...
Page 55: Related Documents
Feature History for IP Table 2-1 lists the release history for this feature. Table 2-2 Feature History for IP Feature Name Releases Feature Information 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 2-15...
Page 56 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 57: Routing
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m A R T Routing...
Page 58 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m...
Page 59: Configuring Ospfv2
You can divide OSPFv2 networks into areas. Routers send most LSAs only within one area, which reduces the CPU and memory requirements for an OSPF-enabled router. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 60: Hello Packet
The two OSPFv2 interfaces must match the following criteria: Hello interval • Dead interval • Area ID (see the “Areas” section on page 3-4) • Authentication • Optional capabilities • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 61: Adjacency
The routers follow an election procedure based on which routers declare themselves in the DR and BDR fields and the priority field in the Hello packet. As a final tie breaker, OSPFv2 chooses the highest router IDs as the DR and BDR. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 62: Areas
ID of 0. If you have more than one area, then one or more routers become area (ABRs). An ABR connects to both the backbone area and at least one other defined area border routers (see Figure 3-2). Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 63: Link-State Advertisements
Flooding and LSA Group Pacing, page 3-6 • Link-State Database, page 3-7 • Opaque LSAs, page 3-7 • LSA Types Table 3-1 shows the LSA types supported by Cisco NX-OS. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 64: Link Cost
By default, LSAs with link-state refresh times within four minutes of each other are grouped together. You should lower this value for large link-state databases or raise it for smaller databases to optimize the OSPFv2 load on your network. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 65: Link-State Database
MaxAge. Routers flood a repeat of the LSA every 30 minutes to prevent accurate link-state information from being aged out. Cisco NX-OS supports the LSA grouping feature to prevent all LSAs from refreshing at the same time. For more information, see the “Flooding and LSA Group Pacing”...
Page 66: Simple Password Authentication
You should use MD5 authentication to authenticate OSPFv2 messages. You configure a password that is shared at the local router and all remote OSPFv2 neighbors. For each OSPFv2 message, Cisco NX-OS creates an MD5 one-way message digest based on the message itself and the encrypted password. The interface sends this digest with the OSPFv2 message.
Page 67: Not-So-Stubby Area
Virtual links allow you to connect an OSPFv2 area ABR to a backbone area ABR when a direct physical connection is not available. Figure 3-4 shows a virtual link that connects Area 3 to the backbone area through Area 5. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 68: Route Redistribution
To take advantage of summarization, you should assign network numbers in areas in a contiguous way to be able to lump these addresses into one range. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-10...
Page 69: Ospfv2 Stub Router Advertisements
OSPFv2 interface. All remote links are marked with the maximum cost (0xFFFF). Multiple OSPFv2 Instances Cisco NX-OS supports multiple instances of the OSPFv2 protocol that run on the same node. You cannot configure multiple instances over the same interface. By default, every instance uses the same system router ID.
Page 70: Prerequisites For Ospfv2
Cisco NX-OS displays areas in dotted decimal notation regardless of whether you enter the area in • decimal or dotted decimal notation. If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
Page 71: Configuring Basic Ospfv2
DETAILED STEPS Command Purpose Enters configuration mode. Step 1 configure terminal Example: switch# configure terminal switch(config)# Enables the OSPFv2 feature. Step 2 feature ospf Example: switch(config)# feature ospf Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-13...
Page 72: Creating An Ospfv2 Instance
OSPFv2 must be able to obtain a router identifier (for example, a configured loopback address) or you must configure the router ID option. SUMMARY STEPS configure terminal router ospf instance-tag (Optional) router-id ip-address (Optional) show ip ospf instance-tag (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-14...
Page 73: Configuring Optional Parameters On An Ospfv2 Instance
“Configuring Advanced OSPFv2” section on page 3-22. BEFORE YOU BEGIN Ensure that you have enabled the OSPF feature (see the “Enabling the OSPFv2 Feature” section on page 3-13). Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-15...
Page 74: Configuring Networks In Ospfv2
BEFORE YOU BEGIN Ensure that you have enabled the OSPF feature (see the “Enabling the OSPFv2 Feature” section on page 3-13). SUMMARY STEPS configure terminal interface interface-type slot/port Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-16...
Page 75 Example: switch(config-if)# show ip ospf 201 interface ethernet 1/2 (Optional) Saves this configuration change. Step 7 copy running-config startup-config Example: switch(config)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-17...
Page 76: Configuring Authentication For An Area
Configuring Authentication for an Area You can configure authentication for all networks in an area or for individual interfaces in the area. Interface authentication configuration overrides area authentication. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-18...
Page 77 3-13). Ensure that all neighbors on an interface share the same authentication configuration, including the shared authentication key. Create the key-chain for this authentication configuration. See the Cisco Nexus 3000 Series NX-OS Security Configuration Guide. SUMMARY STEPS configure terminal...
Page 78: Configuring Authentication For An Interface
3-13). Ensure that all neighbors on an interface share the same authentication configuration, including the shared authentication key. Create the key-chain for this authentication configuration. See the Cisco Nexus 3000 Series NX-OS Security Configuration Guide. SUMMARY STEPS configure terminal...
Page 79 21 md5 0 mypass 0—configures the password in clear text. • 3—configures the pass key as 3DES encrypted. • 7—configures the key as Cisco type 7 encrypted. • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-21...
Page 80: Configuring Advanced Ospfv2
Configuring Route Summarization, page 3-34 • Configuring Stub Route Advertisements, page 3-35 • Modifying the Default Timers, page 3-36 • Restarting an OSPFv2 Instance, page 3-39 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-22...
Page 81: Configuring Filter Lists For Border Routers
Filters incoming or outgoing Network Summary (type Step 3 area area-id filter-list route-map 3) LSAs on an ABR. map-name {in | out} Example: switch(config-router)# area 0.0.0.10 filter-list route-map FilterLSAs in Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-23...
Page 82: Configuring Stub Areas
Ensure that there are no virtual links or ASBRs in the proposed stub area. SUMMARY STEPS configure terminal router ospf instance-tag area area-id stub (Optional) area area-id default-cost cost (Optional) show ip ospf instance-tag (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-24...
Page 83: Configuring A Totally Stubby Area
You can create a totally stubby area and prevent all summary route updates from going into the stub area. To create a totally stubby area, use the following command in router configuration mode: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-25...
Page 84: Configuring Nssa
[no-redistribution] [default-information-originate [route-map map-name]] [no-summary] [translate type7 {always | never} [suppress-fa]] (Optional) area area-id default-cost cost (Optional) show ip ospf instance-tag (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-26...
Page 85 This example shows how to create an NSSA that filters external routes and blocks all summary route updates: switch# configure terminal switch(config)# router ospf 201 switch(config-router)# area 0.0.0.10 nssa route-map ExternalFilter no-summary switch(config-router)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-27...
Page 86: Configuring Virtual Links
“Enabling the OSPFv2 Feature” section on page 3-13). SUMMARY STEPS configure terminal router ospf instance-tag area area-id virtual-link router-id (Optional) show ip ospf virtual-link [brief] (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-28...
Page 87 50 (Optional) Configures the OSPFv2 hello interval, in hello-interval seconds seconds. The range is from 1 to 65535. The default is 10 Example: seconds. switch(config-router-vlink)# hello-interval 25 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-29...
Page 88: Configuring Redistribution
Default information originate ignores match statements in the optional route map. Note Default metric—Sets all redistributed routes to the same cost metric. • If you redistribute static routes, Cisco NX-OS also redistributes the default static route. Note BEFORE YOU BEGIN Ensure that you have enabled the OSPF feature (see the “Enabling the OSPFv2 Feature”...
Page 89 25 connected routes. (Optional) Saves this configuration change. Step 6 copy running-config startup-config Example: switch(config-router)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-31...
Page 90: Limiting The Number Of Redistributed Routes
{bgp id | direct| eigrp id | ospf id | rip id | static} route-map map-name redistribute maximum-prefix max [threshold] [warning-only | withdraw [num-retries timeout]] (Optional) show running-config ospf (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-32...
Page 91 This example shows how to limit the number of redistributed routes into OSPF: switch# configure terminal switch(config)# router ospf 201 switch(config-router)# redistribute bgp route-map FilterExternalBGP switch(config-router)# redistribute maximum-prefix 1000 75 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-33...
Page 92: Configuring Route Summarization
[no-advertise | tag tag] summary address that can be used for redistribution Example: with route maps. switch(config-router)# summary-address 10.5.0.0/16 tag 2 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-34...
Page 93: Configuring Stub Route Advertisements
You should not save the running configuration of a router when it is configured for a graceful shutdown Note because the router will continue to advertise a maximum metric after it is reloaded. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-35...
Page 94: Modifying The Default Timers
At the interface level, you can also control the following timers: Retransmit interval—Sets the estimated time between successive LSAs. • Transmit delay—Sets the estimated time to transmit an LSA to a neighbor. • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-36...
Page 95 Sets the LSA arrival time in milliseconds. The range is Step 3 timers lsa-arrival msec from 10 to 600000. The default is 1000 milliseconds. Example: switch(config-router)# timers lsa-arrival 2000 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-37...
Page 96 Step 12 ip ospf transmit-delay seconds to a neighbor. The range is from 1 to 450. The default Example: is 1. switch(config-if)# ip ospf transmit-delay 450 switch(config-if)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-38...
Page 97: Restarting An Ospfv2 Instance
Ensure that you have enabled the OSPF feature (see the “Enabling the OSPFv2 Feature” section on page 3-13). SUMMARY STEPS configure terminal vrf context vrf_name router ospf instance-tag Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-39...
Page 98 Step 6 interface interface-type slot/port Example: switch(config-router-vrf)# interface ethernet 1/2 switch(config-if)# Configures the interface as a Layer 3 routed interface. Step 7 no switchport Example: switch(config-if)# no switchport Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-40...
Page 99: Verifying The Ospfv2 Configuration
[vrf Displays the OSPFv2 interface configuration. {vrf-name | all | default | management}] Displays the OSPFv2 LSAs that have changed. show ip ospf lsa-content-changed-list interface type number Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-41...
Page 100: Displaying Ospfv2 Statistics
[vrf {vrf-name | all | default | management}] Configuration Examples for OSPFv2 This example shows how to configure OSPFv2: feature ospf router ospf 201 router-id 290.0.2.1 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-42...
Page 101: Additional References
Feature History for OSPFv2 Table 3-3 lists the release history for this feature. Table 3-3 Feature History for IOSPFv2 Feature Name Releases Feature Information OSPFv2 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 3-43...
Page 102 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 103 This process speeds convergence and minimizes the bandwidth used by EIGRP. This section includes the following topics: EIGRP Components, page 4-2 • EIGRP Route Updates, page 4-3 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 104: Configuring Eigrp
EIGRP also uses the Hello messages as a keepalive to its neighbors. As long as Hello messages are received, Cisco NX-OS can determine that a neighbor is alive and functioning. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 105: Diffusing Update Algorithm
Delay—The sum of the delays configured on the interfaces that make up the route to the destination • network. Configured in tens of microseconds. Bandwidth—The calculation from the lowest configured bandwidth on an interface that is part of • the route to the destination. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 106: Advanced Eigrp
Stub Routers, page 4-5 • Route Summarization, page 4-6 • Route Redistribution, page 4-6 • Load Balancing, page 4-6 • Split Horizon, page 4-6 • Virtualization Support, page 4-7 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 107: Address Families
Key-chain management allows you to control changes to the authentication keys used by MD5 authentication digest. See the Cisco Nexus 3000 Series NX-OS Security Configuration Guide, for more details about creating key-chains.
Page 108: Route Summarization
Cisco NX-OS supports the Equal Cost Multiple Paths (ECMP) feature with up to 16 equal-cost paths in the EIGRP route table and the unicast RIB. You can configure EIGRP to load balance traffic across some or all of those paths.
Page 109: Virtualization Support
Split horizon is a method that controls the sending of EIGRP update and query packets. When you enable split horizon on an interface, Cisco NX-OS does not send update and query packets for destinations that were learned from this interface. Controlling update and query packets in this manner reduces the possibility of routing loops.
Page 110: Default Settings
• Cisco NX-OS supports only IP. • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Default Settings Table 4-1 lists the default settings for EIGRP parameters.
Page 111: Configuring Basic Eigrp
DETAILED STEPS Command Purpose Enters configuration mode. Step 1 configure terminal Example: switch# configure terminal switch(config)# Enables the EIGRP feature. Step 2 feature eigrp Example: switch(config)# feature eigrp Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 112: Creating An Eigrp Instance
SUMMARY STEPS configure terminal router eigrp instance-tag (Optional) autonomous-system as-number (Optional) log-adjacency-changes (Optional) log-neighbor-warnings [seconds] interface interface-type slot/port no switchport ip router eigrp instance-tag show ip eigrp interfaces Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-10...
Page 113 Associates this interface with the configured EIGRP Step 8 ip router eigrp instance-tag process. The instance tag can be any case-sensitive, Example: alphanumeric string up to 20 characters. switch(config-if)# ip router eigrp Test1 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-11...
Page 114: Restarting An Eigrp Instance
Restarts the EIGRP instance and removes all restart eigrp instance-tag neighbors. The instance tag can be any Example: case-sensitive, alphanumeric string up to 20 switch(config)# restart eigrp Test1 characters. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-12...
Page 115: Shutting Down An Eigrp Instance
Test1 shutdown Configuring Advanced EIGRP This section includes the following topics: Configuring Authentication in EIGRP, page 4-14 • Configuring EIGRP Stub Routing, page 4-16 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-13...
Page 116: Configuring Authentication In Eigrp
4-9). Ensure that all neighbors for an EIGRP process share the same authentication configuration, including the shared authentication key. Create the key-chain for this authentication configuration. See the Cisco Nexus 3000 Series NX-OS Security Configuration Guide. SUMMARY STEPS configure terminal...
Page 117 VRF Example: mode. switch(config-if)# ip authentication key-chain eigrp Test1 routeKeys The instance tag can be any case-sensitive, alphanumeric string up to 20 characters. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-15...
Page 118: Configuring Eigrp Stub Routing
The last line of the output shows the stub status of the remote or spoke router. This example shows the output from the show ip eigrp neighbor detail command: Router# show ip eigrp neighbor detail Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-16...
Page 119: Configuring A Summary Address For Eigrp
You must create a route map to control the types of routes that are redistributed into EIGRP. See Chapter 11, “Configuring Route Policy Manager.” SUMMARY STEPS configure terminal Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-17...
Page 120 The default values are as follows: Example: bandwidth—100000 Kb/s switch(config-router-af)# default-metric • 500000 30 200 1 1500 delay—100 (10 microsecond units) • reliability—255 • loading—1 • MTU—1492 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-18...
Page 121: Limiting The Number Of Redistributed Routes
{bgp id | direct | eigrp id | ospf id | rip id | static} route-map map-name redistribute maximum-prefix max [threshold] [warning-only | withdraw [num-retries timeout]] (Optional) show running-config eigrp Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-19...
Page 122 This example shows how to limit the number of redistributed routes into EIGRP: switch# configure terminal switch(config)# router eigrp Test1 switch(config-router)# redistribute bgp route-map FilterExternalBGP switch(config-router)# redistribute maximum-prefix 1000 75 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-20...
Page 123: Configuring Load Balancing In Eigrp
Enters the address-family configuration mode. Step 3 address-family ipv4 unicast This command is optional for IPv4. Example: switch(config-router)# address-family ipv4 unicast switch(config-router-af)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-21...
Page 124: Adjusting The Interval Between Hello Packets And The Hold Time
20 characters. The range is Example: from 1 to 65535. switch(config-if)# ip hold-time eigrp Test1 30 Use the show ip eigrp interface detail command to verify timer configuration. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-22...
Page 125: Disabling Split Horizon
Routes over this maximum are advertised as Example: unreachable. The range is from 1 to 255. The switch(config-router-af)# metric default is 100. maximum-hops 70 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-23...
Page 126 {prefix-list name | route-map name} {in | out} and route map name can be any case-sensitive, alphanumeric string up to 20 characters. Example: switch(config-if)# ip distribute-list eigrp Test1 route-map EigrpTest in Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-24...
Page 127: Configuring Virtualization For Eigrp
Create the VRFs. SUMMARY STEPS configure terminal vrf context vrf-name router eigrp instance-tag interface ethernet slot/port no switchport vrf member vrf-name ip router eigrp instance-tag (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-25...
Page 128 Example: to 20 characters. switch(config-if)# ip router eigrp Test1 (Optional) Saves this configuration change. Step 8 copy running-config startup-config Example: switch(config-if)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-26...
Page 129: Verifying The Eigrp Configuration
Displays accounting statistics for EIGRP. [vrf vrf-name] show ip eigrp [instance-tag] route-map Displays redistribution statistics for EIGRP. statistics redistribute show ip eigrp [instance-tag] traffic [vrf Displays traffic statistics for EIGRP. vrf-name] Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-27...
Page 130: Configuration Examples For Eigrp
Additional References For additional information related to implementing EIGRP, see the following sections: Related Documents, page 4-29 • MIBs, page 4-29 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-28...
Page 131: Related Documents
Feature History for EIGRP Table 4-2 lists the release history for this feature. Table 4-2 Feature History for EIGRP Feature Name Releases Feature Information EIGRP 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 4-29...
Page 132 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 133: Configuring Basic Bgp
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m C H A P T E R Configuring Basic BGP This chapter describes how to configure Border Gateway Protocol (BGP) on a Cisco NX-OS switch. This chapter includes the following sections: Information About Basic BGP, page 5-1 •...
Page 134: Bgp Autonomous Systems
BGP (iBGP) peering sessions. 4-Byte AS Number Support BGP supports 2-byte or 4-byte AS numbers. Cisco NX-OS displays 4-byte AS numbers in plain-text notation (that is, as 32-bit integers). You can configure 4-byte AS numbers as either plain-text notation (for example, 1 to 4294967295), or AS.dot notation (for example, 1.0).
Page 135: Bgp Peers
Dynamic AS Numbers for Prefix Peers Cisco NX-OS accepts a range or list of AS numbers to establish BGP sessions. For example, if you configure BGP to use IPv4 prefix 192.0.2.0/8 and AS numbers 33, 66, and 99, BGP establishes a session with 192.0.2.1 with AS number 66 but rejects a session from 192.0.2.2 with AS number 50.)
Page 136: Bgp Router Identifier
A, B, and C. When Cisco NX-OS compares A and B, it chooses A. When Cisco NX-OS compares B and C, it chooses B. But when Cisco NX-OS compares A and C, it might not choose A because some BGP metrics apply only among paths from the same neighboring autonomous system and not among all paths.
Page 137 6-8 for more information. If one path is from an internal peer and the other path is from an external peer, then Cisco NX-OS chooses the path from the external peer. If the paths have different IGP metrics to their next-hop addresses, then Cisco NX-OS chooses the path with the lower IGP metric.
Page 138: Step 2-Determining The Order Of Comparisons
If the path includes an originator attribute, then Cisco NX-OS uses that attribute as the router ID to compare to; otherwise, Cisco NX-OS uses the router ID of the peer that sent the path. If the paths have different router IDs, Cisco NX-OS chooses the path with the lower router ID.
Page 139: Bgp And The Unicast Rib
License Requirement Cisco NX-OS BGP requires a LAN Enterprise Services license. For a complete explanation of the Cisco NX-OS licensing scheme and how to obtain and apply licenses, see the Cisco NX-OS Licensing Guide. Make sure the LAN Base Services license is installed on the switch to enable Layer 3 interfaces.
Page 140: Guidelines And Limitations For Bgp
For more information, see Chapter 6, “Configuring Advanced BGP.” This example shows how to enter router configuration mode: switch# configuration switch(config)# router bgp 64496 switch(config-router)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 141 Neighbor Configuration Mode Cisco NX-OS provides the neighbor configuration mode to configure BGP peers. You can use neighbor configuration mode to configure all parameters for a peer. This example shows how to enter neighbor configuration mode: switch(config)# router bgp 64496 switch(config-router)# neighbor 192.0.2.1...
Page 142 Shutting Down BGP, page 5-14 • Configuring BGP Peers, page 5-14 • Configuring Dynamic AS Numbers for Prefix Peers, page 5-16 • Clearing BGP Information, page 5-18 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-10...
Page 143: Enabling The Bgp Feature
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
Page 144: Creating A Bgp Instance
| multicast} mode for the IPv4 address family. This command Example: triggers an automatic notification and session reset for switch(config-router)# address-family all BGP neighbors. ipv4 unicast switch(config-router-af)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-12...
Page 145: Restarting A Bgp Instance
To restart a BGP instance and remove all associated peers, use the following command: Command Purpose Restarts the BGP instance and resets or restart bgp instance-tag reestablishes all peering sessions. Example: switch(config)# restart bgp 201 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-13...
Page 146: Shutting Down Bgp
(Optional) description text (Optional) timers keepalive-time hold-time (Optional) shutdown address-family ipv4 {unicast | multicast} (Optional) show bgp ipv4 {unicast | multicast} neighbors (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-14...
Page 147 {unicast | multicast} neighbors Example: switch(config-router-neighbor-af)# show bgp ipv4 unicast neighbors (Optional) Saves this configuration change. Step 9 copy running-config startup-config Example: switch(config-router-neighbor-af) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-15...
Page 148: Configuring Dynamic As Numbers For Prefix Peers
32-bit integer in the form of a higher 16-bit switch(config)# router bgp 64496 decimal number and a lower 16-bit decimal number in switch(config-router)# xx.xx format. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-16...
Page 149 192.0.2.0/8 remote-as route-map BGPPeers switch(config-router-neighbor)# description Peer Router B switch(config-router-neighbor)# address-family ipv4 unicast switch(config-router-neighbor-af)# copy running-config startup-config Chapter 11, “Configuring Route Policy Manager” for information on route maps. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-17...
Page 150: Clearing Bgp Information
{unicast | multicast} flap-statistics Clears route flap statistics in the selected address [vrf vrf-name] family. The vrf-name can be any case-sensitive, alphanumeric string up to 64 characters. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-18...
Page 151 All neighbors within that • prefix are cleared. vrf-name—VRF name. All neighbors in that • VRF are cleared. The name can be any case-sensitive, alphanumeric string up to 64 characters. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-19...
Page 152 All neighbors within that • prefix are cleared. vrf-name—VRF name. All neighbors in that • VRF are cleared. The name can be any case-sensitive, alphanumeric string up to 64 characters. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-20...
Page 153: Verifying The Basic Bgp Configuration
[non-transitive | transitive] aa4:nn [exact-match]} [vrf vrf-name] show bgp ip {unicast | multicast} [ip-address] Displays the BGP routes that match a BGP extcommunity-list list-name [exact-match] [vrf extended community list. vrf-name] Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-21...
Page 154 This command has multiple options. See the Cisco Nexus 3000 Series Command Reference,, for more information. Displays the current running BGP configuration. show running-configuration bgp Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-22...
Page 155: Displaying Bgp Statistics
Route redistribution • Route maps • Additional References For additional information related to implementing BGP, see the following sections: Related Documents, page 5-24 • MIBs, page 5-24 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-23...
Page 156: Related Documents
Feature History for BGP Table 5-3 lists the release history for this feature. Table 5-3 Feature History for BGP Feature Name Releases Feature Information 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 5-24...
Page 157: Configuring Advanced Bgp
BGP is an interdomain routing protocol that provides loop-free routing between organizations or autonomous systems. Cisco NX-OS supports BGP version 4. BGP version 4 includes multiprotocol extensions that allow BGP to carry routing information for IP multicast routes and multiple Layer 3 protocol address families.
Page 158: Peer Templates
A peer-policy template can inherit from a set of peer-policy templates. Cisco NX-OS evaluates these peer-policy templates in the order specified by the preference value in the inherit configuration. The lowest number is preferred over higher numbers.
Page 159: Route Policies And Resetting Bgp Sessions
If you change the inbound route policy, Cisco NX-OS passes these stored routes through the modified inbound route policy to update the route table without tearing down existing peering sessions. Soft reconfiguration inbound can use significant memory resources to store the unfiltered BGP routes.
Page 160: As Confederations
Figure 6-2 shows the BGP network from Figure 6-1, split into two subautonomous systems and one confederation. Figure 6-2 AS Confederation AS20 AS10 eBGP Confederation peers iBGP iBGP Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 161: Route Reflector
Capabilities negotiation allows BGP to use only the set of features supported by both BGP peers on a link. If a BGP peer does not support capabilities negotiation, Cisco NX-OS will attempt a new session to the peer without capabilities negotiation if you have configured the address family as IPv4.
Page 162: Route Dampening
When you configure a route reflector for iBGP multipath, and the route reflector advertises the selected Note best path to its peers, the next hop for the path is not modified. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 163: Route Aggregation
• First hop IP address or first hop interface changes. • Next hop becomes connected. • Next hop becomes unconnected. • Next hop becomes a local address. • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 164: Route Redistribution
Tuning the Best-Path Algorithm You can modify the default behavior of the best-path algorithm through optional configuration parameters, including changing how the algorithm handles the MED attribute and the router ID. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 165: Multiprotocol Bgp
Virtualization Support Cisco NX-OS supports multiple instances of BGP that run on the same system. BGP supports Virtual Routing and Forwarding instances (VRFs). By default, Cisco NX-OS places you in the default VRF unless you specifically configure another VRF.
Page 166: Guidelines And Limitations For Bgp
• Configuring BGP Peer Templates, page 6-16 • Configuring Prefix Peering, page 6-18 • Configuring BGP Authentication, page 6-19 • Resetting a BGP Session, page 6-20 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-10...
Page 167 • Configuring Virtualization, page 6-36 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Configuring BGP Session Templates You can use BGP session templates to simplify BGP configuration for multiple BGP peers with similar configuration needs.
Page 168 Step 5 timers keepalive hold values to the peer-session template. Example: The default keepalive interval is 60. The default hold switch(config-router-stmp)# timers 30 90 time is 180. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-12...
Page 169 Use the show bgp neighbor command to see the template applied. See the Cisco Nexus 3000 Series Command Reference,, for details on all commands available in the template. This example shows how to configure a BGP peer-session template and apply it to a BGP peer:...
Page 170 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco NX-OS evaluates multiple peer policies for an address family using the preference value. The lowest preference value is evaluated first.
Page 171 Use the show bgp neighbor command to see the template applied. See the Cisco Nexus 3000 Series Command Reference,, for details on all commands available in the template. This example shows how to configure a BGP peer-session template and apply it to a BGP peer: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 172: Configuring Bgp Peer Templates
(Optional) address-family ipv4 {multicast | unicast} (Optional) inherit peer template-name exit (Optional) timers keepalive hold exit neighbor ip-address inherit peer template-name (Optional) timers keepalive hold (Optional) show bgp peer-template template-name Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-16...
Page 173 These values override the timer values in the Example: peer-session template, BaseSession. switch(config-router-neighbor)# timers 45 100 Exits BGP peer template configuration mode. Step 9 exit Example: switch(config-router-neighbor)# exit switch(config-router)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-17...
Page 174: Configuring Prefix Peering
When a BGP peer that is part of a prefix peering disconnects, Cisco NX-OS holds its peer structures for a defined prefix peer timeout value. An established peer can reset and reconnect without danger of being blocked because other peers have consumed all slots for that prefix peering.
Page 175: Configuring Bgp Authentication
To configure BGP to use MD5 authentication, use the following command in neighbor configuration mode: Command Purpose Configures an MD5 password for BGP neighbor password [0 | 3 | 7] string sessions. Example: switch(config-router-neighbor)# password BGPpassword Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-19...
Page 176: Resetting A Bgp Session
If you modify a route policy for BGP, you must reset the associated BGP peer sessions. If the BGP peers do not support route refresh, you can configure a soft reconfiguration for inbound policy changes. Cisco NX-OS automatically attempts a soft reset for the session.
Page 177: Configuring Bgp Next-Hop Address Tracking
You can disable capabilities negotiations to interoperate with older BGP peers that do not support capabilities negotiation. To disable capabilities negotiation, use the following command in neighbor configuration mode: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-21...
Page 178: Configuring Ebgp
Configures the eBGP TTL value for eBGP ebgp-multihop ttl-value multihop. The range is from 2 to 255. You must Example: manually reset the BGP sessions after using this switch(config-router-neighbor)# command. ebgp-multihop 5 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-22...
Page 179: Disabling A Fast External Failover
BGP neighbor sessions. identifier 4000 To configure the autonomous systems that belong to the AS confederation, use the following command in router configuration mode: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-23...
Page 180: Configuring Route Reflector
{unicast | multicast} (Optional) client-to-client reflection exit neighbor ip-address remote-as as-number address-family ipv4 {unicast | multicast} route-reflector-client show bgp ip {unicast | multicast} neighbors (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-24...
Page 181 Configures the switch as a BGP route reflector and Step 9 route-reflector-client configures the neighbor as its client. This command Example: triggers an automatic notification and session reset for switch(config-router-neighbor-af)# the BGP neighbor sessions. route-reflector-client Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-25...
Page 182: Configuring Route Dampening
Configures the maximum number of equal-cost maximum-paths [ibgp] maxpaths paths for load sharing. The range is from 1 to 16. Example: The default is 8. switch(config-router-af)# maximum-paths 12 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-26...
Page 183: Configuring Maximum Prefixes
Enables dynamic capability. This command dynamic-capability triggers an automatic notification and session reset Example: for the BGP neighbor sessions. switch(config-router-neighbor)# This command is disabled by default. dynamic-capability Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-27...
Page 184: Configuring Aggregate Addresses
BEFORE YOU BEGIN Ensure that you have enabled the BGP feature (see the “Enabling the BGP Feature” section on page 5-11). SUMMARY STEPS configure terminal router bgp as-number Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-28...
Page 185 BGP routing and configures the neighbor IP address. Example: switch(config-router)# neighbor 192.168.1.2 remote-as 65537 switch(config-router-neighbor)# Enters address family configuration mode. Step 4 address-family ipv4 {unicast | multicast} Example: switch(config-router-neighbor)# address-family ipv4 multicast switch(config-router-neighbor-af)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-29...
Page 186: Configuring Route Redistribution
You can configure BGP to accept routing information from another routing protocol and redistribute that information through the BGP network. Optionally, you can assign a default route for redistributed routes. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-30...
Page 187 (Optional) Generates a default route into BGP. Step 5 default-metric value Example: switch(config-router-af)# default-metric (Optional) Saves this configuration change. Step 6 copy running-config startup-config Example: switch(config-router-af)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-31...
Page 188: Configuring Multiprotocol Bgp
Places the router in neighbor configuration mode for Step 3 neighbor ip-address remote-as as-number BGP routing and configures the neighbor IP address. Example: switch(config-router)# neighbor 192.168.1.2 remote-as 65537 switch(config-router-neighbor)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-32...
Page 189: Tuning Bgp
Tuning BGP You can tune BGP characteristics through a series of optional parameters. To tune BGB, use the following ofptional commands in router configuration mode: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-33...
Page 190 The range • is from 0 to 1200 seconds. The default value is You must manually reset the BGP sessions after configuring this command. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-34...
Page 191 2/1 BGP neighbor sessions. To tune BGP, use the following optional commands in neighbor address-family configuration mode: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-35...
Page 192: Configuring Virtualization
“Enabling the BGP Feature” section on page 5-11). SUMMARY STEPS configure terminal vrf context vrf-name exit router bgp as-number vrf vrf-name neighbor ip-address remote-as as-number bestpath as-path multipath-relax Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-36...
Page 193 This example shows how to create a VRF and configure the router ID in the VRF: switch# configure terminal switch(config)# vrf context NewVRF switch(config-vrf)# exit switch(config)# router bgp 65536 switch(config-router)# vrf NewVRF Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-37...
Page 194: Verifying The Advanced Bgp Configuration
{unicast | multicast} [ip-address] Displays the BGP policy information. Use the policy name [vrf vrf-name] clear bgp policy command to clear the policy information. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-38...
Page 195: Displaying Bgp Statistics
Displays the BGP sessions for all peers. Use the clear bgp sessions command to clear these statistics. Displays the BGP statistics. show bgp statistics Related Topics The following topics can give more information on BGP: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-39...
Page 196: Additional References
Feature History for BGP Table 6-2 lists the release history for this feature. Table 6-2 Feature History for BGP Feature Name Releases Feature Information 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 6-40...
Page 197 Split Horizon, page 7-2 • Route Filtering, page 7-3 • Route Summarization, page 7-3 • Route Redistribution, page 7-3 • Load Balancing, page 7-3 • Virtualization Support, page 7-4 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 198: Configuring Rip
Key-chain management allows you to control changes to the authentication keys used by an MD5 authentication digest or simple text password authentication. See the Cisco Nexus 3000 Series NX-OS Security Configuration Guide for more details about creating key-chains.
Page 199: Route Filtering
By default, split horizon is enabled on all interfaces. Route Filtering You can configure a route policy on a RIP-enabled interface to filter the RIP updates. Cisco NX-OS updates the route table with only those routes that the route policy allows.
Page 200: Virtualization Support
RIP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 201 • Tuning RIP, page 7-16 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Enabling the RIP Feature You must enable the RIP feature before you can configure RIP.
Page 202: Creating A Rip Instance
“Enabling the RIP Feature” section on page 7-5). SUMMARY STEPS configure terminal router rip instance-tag address-family ipv4 unicast (Optional) show ip rip [instance instance-tag] [vrf vrf-name] (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 203 Configures the maximum number of equal-cost maximum-paths number paths that RIP maintains in the route table. The Example: switch(config-router-af)# maximum-paths 6 range is from 1 to 16. The default is 16. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 204: Restarting A Rip Instance
SUMMARY STEPS configure terminal interface interface-type slot/port no switchport ip rip instance-tag (Optional) show ip rip [instance instance-tag] interface [interface-type slot/port] [vrf vrf-name] [detail] (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 205: Configuring Rip Authentication
“Enabling the RIP Feature” section on page 7-5). Configure a key chain if necessary before enabling authentication. See the Cisco Nexus 3000 Series NX-OS Security Configuration Guide for details on implementing key chains. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 206 00:00:00 Jan 01 2000 infinite switch(config)# interface ethernet 1/2 switch(config-if)# no switchport switch(config-if)# ip rip authentication mode md5 switch(config-if)# ip rip authentication keychain RIPKey switch(config-if)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-10...
Page 207: Configuring A Passive Interface
Configuring Route Summarization You can create aggregate addresses that are represented in the routing table by a summary address. Cisco NX-OS advertises the summary address metric that is the smallest metric of all the more-specific routes.
Page 208: Configuring Route Redistribution
“Configuring Route Maps” section on page 11-12 ospf | ospfv3 | rip} instance-tag | static} route-map map-name for more information about route maps. Example: switch(config-router-af)# redistribute eigrp 201 route-map RIPmap Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-12...
Page 209: Configuring Virtualization
Ensure that you have enabled the RIP feature (see the “Enabling the RIP Feature” section on page 7-5). SUMMARY STEPS configure terminal vrf vrf-name exit router rip instance-tag Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-13...
Page 210 Example: switch(config)# vrf context RemoteOfficeVRF switch(config-vrf)# (Optional) Configures the VRF address family for this Step 6 address-family ipv4 unicast RIP instance. Example: switch(config-router-vrf)# address-family ipv4 unicast switch(config-router-vrf-af)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-14...
Page 211 VRF. [vrf vrf-name ] Example: switch(config-if)# show ip rip Enterprise ethernet 1/2 (Optional) Saves this configuration change. Step 14 copy running-config startup-config Example: switch(config-if)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-15...
Page 212: Tuning Rip
The range is from 1 to any positive integer. The default is 120. You can use the following optional commands in interface configuration mode to tune RIP: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-16...
Page 213: Verifying The Rip Configuration
[vrf vrf-name] Use the clear ip rip policy command to clear policy statistics. Use the clear ip rip statistics command to clear RIP statistics. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-17...
Page 214: Configuration Examples For Rip
Additional References For additional information related to implementing RIP, see the following sections: Related Documents, page 7-19 • Standards, page 7-19 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-18...
Page 215: Related Documents
Feature History for RIP Table 7-2 lists the release history for this feature. Table 7-2 Feature History for RIP Feature Name Releases Feature Information 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 7-19...
Page 216 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 217: Information About Static Routing
(a default router to which all unroutable packets are sent). This section includes the following topics: Administrative Distance, page 8-2 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 218: Chapter 8 Configuring Static Routing
By default, a router prefers a static route to a dynamic route because a static route has a smaller Note administrative distance than a dynamic route. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 219: Remote Next Hops For Static Routes
Static routing requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 220: Configuring Static Routing
• Configuring Virtualization, page 8-5 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Configuring a Static Route You can configure a static route on the router.
Page 221: Configuring Virtualization
[ pref ] address. The preference value sets the administrative distance. The range is from 1 to 255. The default is 1. Example: switch(config-vrf)# ip route 192.0.2.0/8 ethernet 1/2 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 222: Verifying The Static Routing Configuration
192.0.2.0/8 192.0.2.10 copy running-config startup-config Additional References For additional information related to implementing static routing, see the following sections: Related Documents, page 8-7 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 223: Related Documents
Table 8-2 lists the release history for this feature. Table 8-2 Feature History for Static Routing Feature Name Releases Feature Information Static Routing 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 224 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 225 VRF-Aware Services, page 9-3 • Overview of Layer 3 Virtualization Cisco NX-OS supports virtual routing and forwarding instances (VRFs). Each VRF contains a separate address space with unicast and multicast route tables for IPv4 and makes routing decisions independent of any other VRF.
Page 226: Configuring Layer 3 Virtualization
Router C By default, Cisco NX-OS uses the VRF of the incoming interface to select which routing table to use for a route lookup. You can configure a route policy to modify this behavior and set the VRF that Cisco NX-OS uses for incoming packets.
Page 227: Vrf-Aware Services
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m VRF-Aware Services A fundamental feature of the Cisco NX-OS architecture is that every IP-based feature is VRF aware. The following VRF-aware services can select a particular VRF to reach a remote server or to filter information based on the selected VRF: AAA—See the Cisco Nexus 3000 Series NX-OS Security Configuration Guide, for more...
Page 228: Filtering
For example, you can configure a syslog server to support a particular VRF. Figure 9-3 shows two syslog servers with each server supporting one VRF. syslog server A is configured in VRF Red, so Cisco NX-OS sends only system messages generated in VRF Red to syslog server A. Figure 9-3...
Page 229: Licensing Requirements For Vrfs
VRFs require no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 230: Default Settings
• Setting the VRF Scope, page 9-12 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Creating a VRF You can create a VRF in a switch.
Page 231: Assigning Vrf Membership To An Interface
192.0.2.0/8 ethernet 1/2 switch(config-vrf)# exit switch(config)# copy running-config startup-config Assigning VRF Membership to an Interface You can make an interface a member of a VRF. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 232 Example: switch(config-vrf)# show vrf Enterprise interface ethernet 1/2 (Optional) Saves this configuration change. Step 6 copy running-config startup-config Example: switch(config)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 233: Configuring Vrf Parameters For A Routing Protocol
Creates a new OSPFv2 instance with the configured Step 2 router ospf instance-tag instance tag. Example: switch(config-vrf)# router ospf 201 switch(config-router)# Enters VRF configuration mode. Step 3 vrf vrf-name Example: switch(config-router)# vrf RemoteOfficeVRF switch(config-router-vrf)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 234: Configuring A Vrf-Aware Service
VRFs. This section uses SNMP and IP domain lists as example services for the detailed configuration steps. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 9-10...
Page 235 This example shows how to Filter SNMP information for VRF Blue to SNMP host 192.0.2.12, reachable on VRF Red: switch# configure terminal switch(config)# vrf definition Blue switch(config-vrf)# snmp-server host 192.0.2.12 use-vrf Red switch(config)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 9-11...
Page 236: Setting The Vrf Scope
Configuration Examples for VRF This example shows how to configure VRF Red, add an SNMP server to that VRF, and add an instance of OSPF to VRF Red: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 9-12...
Page 237 Cisco Nexus 3000 Series NX-OS System Management Configuration Guide Additional References For additional information related to implementing virtualization, see the following sections: Related Documents, page 9-14 • Standards, page 9-14 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 9-13...
Page 238: Related Documents
Feature History for VRF Table 9-2 lists the release history for this feature. Table 9-2 Feature History for VRF Feature Name Releases Feature Information 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 9-14...
Page 239: Managing The Unicast Rib And Fib
• Feature History for Unicast RIB and FIB, page 10-10 • Information About the Unicast RIB and FIB The unicast RIB (IPv4 RIB) and FIB are part of the Cisco NX-OS forwarding architecture, as shown in Figure 10-1. Figure 10-1...
Page 240: Layer 3 Consistency Checker
• Layer 3 Consistency Checker In rare instances, an inconsistency can occur between the unicast RIB and the FIB on each module. Cisco NX-OS supports the Layer 3 consistency checker. This feature detects inconsistencies between the unicast IPv4 RIB and the FIB on each interface module. Inconsistencies include the following: Missing prefix •...
Page 241: Chapter 10 Managing The Unicast Rib And Fib
The unicast RIB and FIB require no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 242: Configuring Load Sharing In The Unicast Fib
Universal ID—Sets the random seed for the hash algorithm. You do not need to configure the • Universal ID. Cisco NX-OS chooses the Universal ID if you do not configure it. Load sharing uses the same path for all packets in a given flow. A flow is defined by the load-sharing Note method that you configure.
Page 243: Configuring Per-Packet Load Sharing
You can use per-packet load sharing to evenly distribute data traffic in an IP network over multiple equal-cost connections. Per-packet load sharing allows the router to send successive data packets over paths on a packet-by-packet basis rather than on a per-flow basis. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 10-5...
Page 244: Displaying Routing And Adjacency Information
You configure per-packet load sharing on the input interface. This configuration determines the output interface that Cisco NX-OS chooses for the packet. For example, if you have ECMP paths on two output interfaces, Cisco NX-OS uses the following load-sharing methods for input packets on Ethernet 1/1: Per-packet load sharing if you configure per-packet load sharing on Ethernet 1/1.
Page 245: Triggering The Layer 3 Consistency Checker
Triggering the Layer 3 Consistency Checker You can manually trigger the Layer 3 consistency checker. To manually trigger the Layer 3 consistency checker, use the following commands in global configuration mode: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 10-7...
Page 246: Clearing Forwarding Information In The Fib
• switch(config)# clear forwarding ipv4 route * The vrf-name can be any case-sensitive, alphanumeric string up to 32 characters. The slot range is from 1 to 10. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 10-8...
Page 247: Estimating Memory Requirements For Routes
IP prefix. • 10.2.2.2 next-hop—The next-hop address • interface—The interface to reach the next-hop • address. The vrf-name can be any case-sensitive, alphanumeric string up to 32 characters. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 10-9...
Page 248: Verifying The Unicast Rib And Fib Configuration
Table 10-1 Feature History for Unicast RIB and FIB Feature Name Releases Feature Information Unicast RIB and FIB 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 10-10...
Page 249: Information About Route Policy Manager
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m C H A P T E R Configuring Route Policy Manager This chapter describes how to configure the Route Policy Manager on the Cisco NX-OS switch. This chapter includes the following sections: Information About Route Policy Manager, page 11-1 •...
Page 250: Route Maps
Cisco NX-OS assigns a sequence number automatically. Cisco NX-OS evaluates prefix lists starting with the lowest sequence number. Cisco NX-OS processes the first successful match for a given prefix. Once a match occurs, Cisco NX-OS processes the permit or deny statement and does not evaluate the rest of the prefix list.
Page 251: Match Criteria
IP packet. When Cisco NX-OS processes a route or packet through a route map, it compares the route or packet to each of the match statements configured. If the route or packet matches the configured criteria, Cisco NX-OS processes it based on the permit or deny configuration for that match entry in the route map and any set criteria configured.
Page 252: As-Path Lists For Bgp
A regular expression. • See the Cisco Nexus 3000 Series Command Reference,, for more information on regular expressions. Extended Community Lists for BGP Extended community lists support 4-byte AS numbers. You can configure community attributes in the...
Page 253: Route Redistribution And Route Maps
Route Policy Manager requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 254: Configuring Route Policy Manager
• Configuring Route Maps, page 11-12 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Configuring IP Prefix Lists IP prefix lists match the IP packet or route against a list of prefixes and prefix lengths.
Page 255: Configuring Mac Lists
You can configure a MAC list to permit or deny a range of MAC addresses. SUMMARY STEPS configure terminal mac-list name [seq number] {permit | deny} mac-address [mac-mask] Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-7...
Page 256: Configuring As-Path Lists
ASCII string, then the permit or deny condition applies. SUMMARY STEPS configure terminal ip as-path access-list name {deny | permit} expression (Optional) show ip as-path list name (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-8...
Page 257: Configuring Community Lists
Use community lists in a match statement to filter BGP routes based on the community attribute. SUMMARY STEPS configure terminal Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-9...
Page 258 This example shows how to create a community list with two entries: switch# configure terminal switch(config)# ip community-list standard BGPCommunity permit no-advertise 65536:20 switch(config)# ip community-list standard BGPCommunity permit local-AS no-export switch(config)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-10...
Page 259: Configuring Extended Community Lists
Creates an expanded BGP extended community list ip extcommunity-list expanded list-name {deny | permit} expression using a regular expression. Example: switch(config)# ip extcommunity-list expanded BGPExtComplex deny 1.5:[0-9][0-9]_ Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-11...
Page 260: Configuring Route Maps
(Optional) Determines what sequence statement to Step 3 continue seq process next in the route map. Used only for filtering Example: and redistribution. switch(config-route-map)# continue 10 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-12...
Page 261 Matches against one or more IPv4 prefix lists. Use match ip address prefix-list name the ip prefix-list command to create the prefix list. [ name... ] Example: switch(config-route-map)# match ip address prefix-list AllowPrefix Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-13...
Page 262 [ vlan-rang e] Example: switch(config-route-map)# match vlan 3, 5-10 You can configure the following optional set parameters for route maps in route-map configuration mode: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-14...
Page 263 Example: BGP route update. Use the ip extcommunity-list switch(config-route-map)# set extcomm-list command to create the extended community list. BGPextCommunity delete Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-15...
Page 264 255 (100 percent reliable). metric3—Loading. The range is from 1 to 200 • (100 percent loaded). metric4—MTU of the path. The range is from • 1 to 4294967295. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-16...
Page 265: Verifying The Route Policy Manager Configuration
This example shows how to use an address family to configure BGP so that any unicast and multicast routes from neighbor 209.0.2.1 are accepted if they match access list 1: router bgp 64496 address-family ipv4 unicast network 192.0.2.0/24 network 209.165.201.0/27 route-map filterBGP Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-17...
Page 266: Related Topics
Table 11-2 lists the release history for this feature. Table 11-2 Feature History for BGP Feature Name Releases Feature Information Route Policy Manager 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 11-18...
Page 267: First-Hop Redundancy Protocols
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m A R T First-Hop Redundancy Protocols...
Page 268 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m...
Page 269: Information About Hsrp
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m C H A P T E R Configuring HSRP This chapter describes how to configure the Hot Standby Router Protocol (HSRP) on the Cisco NX-OS switch. This chapter includes the following sections: Information About HSRP, page 12-1 •...
Page 270: Hsrp Overview
HSRP. By sharing a virtual MAC address and a virtual IP address, two or more interfaces can act as a single virtual router. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-2...
Page 271: Hsrp For Ipv4
For example, HSRP group 1 uses the HSRP virtual MAC address of 0000.0C07.AC01. Hosts on the adjoining LAN segment use the normal Address Resolution Protocol (ARP) process to resolve the associated MAC addresses. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-3...
Page 272: Hsrp Versions
0 to 4095 and uses a new MAC address range of 0000.0C9F.F000 to 0000.0C9F.FFFF. HSRP Versions Cisco NX-OS supports HSRP version 1 by default. You can configure an interface to use HSRP version HSRP version 2 has the following enhancements to HSRP version 1: Expands the group number range.
Page 273: Object Tracking And Hsrp
Two objects that you can track are the line protocol state of an interface or the reachability of an IP route. If the specified object goes down, Cisco NX-OS reduces the HSRP priority by the configured amount. For more information, see the “Configuring HSRP Object Tracking”...
Page 274: Licensing Requirements For Hsrp
HSRP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 275: Configuring Hsrp
• Customizing HSRP, page 12-14 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Enabling the HSRP Feature You must globally enable the HSRP feature before you can configure and enable any HSRP groups.
Page 276: Configuring The Hsrp Version
“Enabling the HSRP Feature” section on page 12-7). Cisco NX-OS enables an HSRP group once you configure the virtual IP address on any member interface in the group. You should configure HSRP attributes such as authentication, timers, and priority before you enable the HSRP group.
Page 277 You should use the no shutdown command to enable the interface after you finish the configuration. Note This example shows how to configure an HSRP group on Ethernet 1/2: switch# configure terminal switch(config)# interface ethernet 1/2 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-9...
Page 278: Configuring The Hsrp Virtual Mac Address
Authenticating HSRP You can configure HSRP to authenticate the protocol using cleartext or MD5 digest authentication. MD5 authentication uses a key chain (see the Cisco Nexus 3000 Series NX-OS Security Configuration Guide). BEFORE YOU BEGIN Ensure that you have enabled the HSRP feature (see the “Enabling the HSRP Feature”...
Page 279 Step 6 show hsrp [group group-number ] Example: switch(config-if-hsrp)# show hsrp group (Optional) Saves this configuration change. Step 7 copy running-config startup-config Example: switch(config-if-hsrp)# copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-11...
Page 280: Configuring Hsrp Object Tracking
[ipv4] priority [value] track object-number [decrement value] preempt [delay minimum seconds] [reload seconds] [sync seconds] (Optional) show hsrp interface interface-type number (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-12...
Page 281 The value argument specifies a reduction in the priority of Example: an HSRP interface when a tracked object fails. The range is switch(config-if-hsrp)# track 1 decrement 20 from 1 to 255. The default is 10. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-13...
Page 282: Configuring The Hsrp Priority
HSRP, the router could take control over the group and become the active router before you finish customizing the feature. If you plan to customize HSRP, you should do so before you enable the HSRP group. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-14...
Page 283 The range Example: is from 0 to 10000 seconds. The default is 0. switch(config-if)# hsrp delay reload Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-15...
Page 284: Verifying The Hsrp Configuration
90 track 2 decrement 20 ip-address 192.0.2.10 no shutdown Additional References For additional information related to implementing HSRP, see the following sections: Related Documents, page 12-17 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-16...
Page 285: Related Documents
Feature History for HSRP Table 12-2 lists the release history for this feature. Table 12-2 Feature History for HSRP Feature Name Releases Feature Information HSRP 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 12-17...
Page 286 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 287: Information About Vrrp
VRRP Router Priority and Preemption, page 13-4 • VRRP Advertisements, page 13-5 • VRRP Authentication, page 13-5 • VRRP Tracking, page 13-5 • Virtualization Support, page 13-5 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-1...
Page 288: Vrrp Operation
VRRP group r and forwards packets sent to this IP address. Clients 1 through 3 are configured with the default gateway IP address of 10.0.0.1. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-2...
Page 289: Vrrp Benefits
LAN topology in which VRRP is configured so that Routers A and B share the traffic to and from clients 1 through 4. Routers A and B act as backups to each other if either router fails. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-3...
Page 290: Vrrp Router Priority And Preemption
Router C as the new master, even though Router B has not failed. If you disable preemption, VRRP will only switch if the original master recovers or the new master fails. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-4...
Page 291: Vrrp Advertisements
Cisco NX-OS encapsulates the VRRP advertisements in IP packets and sends them to the IP multicast address assigned to the VRRP group. Cisco NX-OS sends the advertisements once every second by default, but you can configure a different advertisement interval.
Page 292: Licensing Requirements For Vrrp
VRRP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 293 • Configuring VRRP Interface State Tracking, page 13-15 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
Page 294: Configuring Vrrp Groups
IP address because the VRRP master is only intended as a next-hop router to forward packets. Some applications require that Cisco NX-OS accept packets addressed to the virtual router IP. Use the secondary option to the virtual IP address to accept these packets when the local router is the VRRP master.
Page 295: Configuring Vrrp Priority
The default priority value for backups is 100. For switches whose interface IP address is the same as the primary virtual IP address (the master), the default value is 255. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-9...
Page 296 Creates a virtual router group. Step 4 vrrp number Example: switch(config-if)# vrrp 250 switch(config-if-vrrp)# Disables the VRRP group. Disabled by default. Step 5 shutdown Example: switch(config-if-vrrp)# shutdown switch(config-if-vrrp)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-10...
Page 297: Configuring Vrrp Authentication
2-7. SUMMARY STEPS configure terminal interface interface-type slot/port no switchport vrrp number shutdown authentication text password no shutdown (Optional) show vrrp (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-11...
Page 298: Configuring Time Intervals For Advertisement Packets
You can configure the time intervals for advertisement packets. BEFORE YOU BEGIN Ensure that you have enabled the VRRP feature (see the “Configuring VRRP” section on page 13-7). Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-12...
Page 299 Sets the interval time in seconds between Step 6 advertisement-interval seconds sending advertisement frames. The range Example: is from 1 to 254. The default is 1 second. switch(config-if-vrrp)# advertisement-interval 15 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-13...
Page 300: Disabling Preemption
2-7. SUMMARY STEPS configure terminal interface interface-type slot/port no switchport vrrp number shutdown no preempt no shutdown (Optional) show vrrp (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-14...
Page 301: Configuring Vrrp Interface State Tracking
Interface state tracking changes the priority of the virtual router based on the state of another interface in the switch. When the tracked interface goes down or the IP address is removed, Cisco NX-OS assigns the tracking priority value to the virtual router. When the tracked interface comes up and an IP address is configured on this interface, Cisco NX-OS restores the configured priority to the virtual router (see the“Configuring VRRP Priority”...
Page 302 Configures the interface as a Layer 3 routed interface. Step 3 no switchport Example: switch(config-if)# no switchport Creates a virtual router group. Step 4 vrrp number Example: switch(config-if)# vrrp 250 switch(config-if-vrrp)# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-16...
Page 303: Verifying The Vrrp Configuration
To display VRRP statistics, use the following commands: Command Purpose Displays the virtual router information. show vrrp vr number interface interface-type port statistics Displays the VRRP statistics. show vrrp statistics Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-17...
Page 304: Configuration Examples For Vrrp
10.1.0.100 no shutdown Router B interface ethernet 1/0 no switchport ip address 10.2.0.1/2 no shutdown vrrp 1 priority 100 authentication text cisco advertisement-interval 3 address 10.2.0.10 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-18...
Page 305 Feature History for VRRP Table 13-2 lists the release history for this feature. Table 13-2 Feature History for VRRP Feature Name Releases Feature Information VRRP 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 13-19...
Page 306 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 307: Information About Object Tracking
Several clients register their interest with the tracking process, track the same object, and take different actions when the object state changes. Clients include the following features: Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-1...
Page 308: Object Track List
Object tracking supports Virtual Routing and Forwarding (VRF) instances. By default, Cisco NX-OS places you in the default VRF unless you specifically configure another VRF. By default, Cisco NX-OS tracks the route reachability state of objects in the default VRF. If you want to track objects in another VRF, you must configure the object to be a member of that VRF (see the “Configuring Object Tracking...
Page 309: Licensing Requirements For Object Tracking
Object tracking requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Page 310: Configuring Object Tracking For An Interface
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Configuring Object Tracking for an Interface You can configure Cisco NX-OS to track the line protocol or IPv4 routing state of an interface. SUMMARY STEPS...
Page 311: Configuring Object Tracking For Route Reachability
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Configuring Object Tracking for Route Reachability You can configure Cisco NX-OS to track the existence and reachability of an IP route. SUMMARY STEPS...
Page 312: Configuring An Object Track List With A Boolean Expression
Example: negates the tracked object state. switch(config-track)# object 10 The example means that when object 10 is up, Note the tracked list detects object 10 as down. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-6...
Page 313: Configuring An Object Track List With A Percentage Threshold
Specifies that the state of the percentage tracked list is based on a configured threshold percent. Example: The track-number range is from 1 to 500. switch(config)# track 1 list threshold percentage switch(config-track# Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-7...
Page 314: Configuring An Object Track List With A Weight Threshold
(combined weight of 20) for the track list to be in the up state. SUMMARY STEPS configure terminal track track-number list threshold weight threshold weight up up-value down down-value object object-number weight value (Optional) show track (Optional) copy running-config startup-config Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-8...
Page 315 In this example, the track list is up if object 10 and object 20 are up, and the track list goes to the down state if all three objects are down. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-9...
Page 316: Configuring An Object Tracking Delay
The tracked object or track list starts the delay timer when a state change occurs but does not recognize a state change until the delay timer expires. At that point, Cisco NX-OS checks the object state again and records a state change only if the object or list currently has a changed state.
Page 317 Track 1 Interface loopback1 Line Protocol Line Protocol is delayed DOWN (8 secs remaining)<------- delay timer counting down 1 changes, last change 00:00:22 Delay down 10 secs Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-11...
Page 318: Configuring Object Tracking For A Nondefault Vrf
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Configuring Object Tracking for a Nondefault VRF You can configure Cisco NX-OS to track an object in a specific VRF. SUMMARY STEPS...
Page 319: Verifying The Object Tracking Configuration
Chapter 12, “Configuring HSRP” • Additional References For additional information related to implementing object tracking, see the following sections: Related Documents, page 14-14 • Standards, page 14-14 • Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-13...
Page 320: Related Documents
Table 14-2 lists the release history for this feature. Table 14-2 Feature History for Object Tracking Feature Name Releases Feature Information Object tracking 5.0(3)U1(1) This feature was introduced. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) 14-14...
Page 321: Appendix
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m A P P E N D I X IETF RFCs This appendix lists the IETF RFCs supported in Cisco NX-OS Release 5.0(3)U1(1) and NX-OS Release 5.0(3)U1(2). BGP RFCs...
Page 322: Appendix A Ietf Rfc
The OSPF Not-So-Stubby Area (NSSA) Option RFC 2370 The OSPF Opaque LSA Option RFC 3137 OSPF Stub Router Advertisement RIP RFCs RFCs Title RFC 2453 RIP Version 2 RFC 2082 RIP-2 MD5 Authentication Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
Page 323: G L O S S A R Y
Active virtual gateway. One virtual gateway within a GLBP group is elected as the active virtual gateway and is responsible for the operation of the protocol. See BDR. backup designated router Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) GL-1...
Page 324 All neighbors establish adjacency with only the designated router and the backup designated router. Diffusing Update Algorithm. EIGRP algorithm used to select optimal routes to a destination. DUAL Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) GL-2...
Page 325 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m External Border Gateway Protocol (BGP). Operates between external systems. eBGP Enhanced Interior Gateway Protocol. A Cisco routing protocol that uses the Diffusing Update EIGRP Algorithm to provide fast convergence and minimized bandwidth utilization.
Page 326 Maximum transmission unit. The largest packet size that a network link will transmit without fragmentation. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) GL-4...
Page 327 A unique identifier used by routing protocols. If not manually configured, the routing protocol selects router ID the highest IP address configured on the system. Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) GL-5...
Page 328 A method of making a physical entity act as multiple, independent logical entities. virtualization Virtual Routing and Forwarding. A method used to create separate, independent Layer 3 entities within a system. Virtual Router Redundancy Protocol. VRRP Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) GL-6...
Page 329 (table) licensing requirements 5-7, 6-9 AS-path lists limitations 5-8, 6-10 configuring 11-8 MIBs 4-29, 5-24 description 11-4 modifying AS-paths 6-34 autonomous system modifying next-hop address 6-20 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-1...
Page 330 5-13 BGP load balancing configuring 6-26 default gateway BGP loadsharing description description default settings BGP multipath. See BGP loadsharing 5-10, 6-10 BGP peers EIGRP authentication (note) Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-2...
Page 331 4-17 description configuring stub routing 11-4 4-16 external BGP. See eBGP creating an instance 4-10 default settings deleting an instance 4-12 description 4-1 to ?? Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-3...
Page 332 12-7 example configuration configuring secondary addresses 12-16 feature history (table) default settings 12-17 guidelines description 12-6 2-1 to 2-6, ?? to 10-2 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-4...
Page 333 14-3 load track list 14-2 load balancing verifying configuration 14-13 Local Proxy ARP virtualization support 14-2 configuring Open Shortest Path First. See OSPF 2-11 description OSPF Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-5...
Page 334 3-42 enable the feature virtual link (figure) 3-13 3-10 example configuration OSPFv2. See OSPF 3-42 feature history (table) 3-43 guidelines 3-12 hello interval Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-6...
Page 335 7-11 11-12 configuring on an interface configuring match parameters 11-13 default settings configuring set parameters 11-14 description description 11-2 disable the feature example configuration 11-17 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-7...
Page 336 Routing Information Protocol. See RIP clearing routes routing metrics 10-9 description description 10-1 displaying routing protocols 10-6 Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-8...
Page 337 13-14 configuring 9-10 preemption 13-4 description VRRP tracking VRF filtering configuring 13-15 description description 13-5 example configuration 9-11 VRF-Lite description guidelines limitations VRF reachability description Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1) IN-9...
Page 338 S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)

Cisco Nexus 3000 Series Configuration Manual

Fib

CHAPTER 2 Configuring Ipv4

Routing

CHAPTER 3 Configuring Ospfv2

Licensing Requirements for Ospfv2

Prerequisites for Ospfv2

Guidelines and Limitations

Default Settings

Configuring Basic Ospfv2

Configuring Advanced Ospfv2

Chapter 4 Configuring EIGRP

Information about Basic BGP

Chapter 5 Configuring Basic BGP

Licensing Requirements for Basic BGP

Prerequisites for BGP

CLI Configuration Modes

Guidelines and Limitations for BGP

Chapter 6 Configuring Advanced BGP

Chapter 7 Configuring RIP

Quick Links

Related Manuals for Cisco Nexus 3000 Series

Summary of Contents for Cisco Nexus 3000 Series