Configuring Load Sharing In The Unicast Fib - Cisco Nexus 7000 Series Configuration Manual

Chapter 15 Managing the Unicast RIB and FIB
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 7 k - d o c f e e d b a c k @ c i s c o . c o m .
Command
show ip fib interfaces module slot
Example:
switch# show ip fib interfaces module
2
show ip fib route module slot
Example:
switch# show ip fib route module 2
show forwarding {ipv4 | ipv6} route
module slot
Example:
switch# show forwarding ipv6 route
module 2
This example shows the FIB contents on a module:
switch# show ip fib route module 2
IPv4 routes for table default/base
------------------+------------------+---------------------
Prefix
------------------+------------------+---------------------
0.0.0.0/32
255.255.255.255/32

Configuring Load Sharing in the Unicast FIB

Dynamic routing protocols, such as Open Shortest Path First (OSPF), support load balancing with
equal-cost multipath (ECMP). The routing protocol determines its best routes based on the metrics
configured for the protocol and installs up to the protocol-configured maximum paths in the unicast RIB.
The unicast RIB compares the administrative distances of all routing protocol paths in the RIB and
selects a best path set from all of the path sets installed by the routing protocols. The unicast RIB installs
this best path set into the FIB for use by the forwarding plane.
The forwarding plane uses a load-sharing algorithm to select one of the installed paths in the FIB to use
for a given data packet.
You can globally configure the following load-sharing settings:
•
•
Note Load sharing uses the same path for all packets in a given flow. A flow is defined by the load-sharing
method that you configure. For example, if you configure source-destination load sharing, then all
packets with the same source IP address and destination IP address pair follow the same path.
OL-20002-02
| Next-hop
Drop
Receive
load-share mode—Selects the best path based on the destination address and port or the source and
the destination address and port.
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.
Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x
Purpose
Displays the FIB interface information for IPv4.
Displays the route table for IPv4.
Displays the route table for IPv4 or IPv6.
| Interface
Null0
sup-eth1
Managing the Unicast RIB and FIB
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