Loopback Interface; Monitoring Ospf; Table 11-3 Show Ip Ospf Statistics Commands - Cisco ONS 15454 SDH Configuration Manual

Chapter 11 Configuring Networking Protocols

Loopback Interface

OSPF uses the highest IP address configured on the interfaces as its router ID. If this interface is down
or removed, the OSPF process must recalculate a new router ID and resend all its routing information
out of its interfaces. If a loopback interface is configured with an IP address, OSPF uses this IP address
as its router ID, even if other interfaces have higher IP addresses. Because loopback interfaces never fail,
this provides greater stability. OSPF automatically prefers a loopback interface over other interfaces, and
it chooses the highest IP address among all loopback interfaces.
Beginning in privileged EXEC mode, follow this procedure to configure a loopback interface:
Command
Step 1
Router# configure terminal
Step 2
Router(config)# interface loopback
0
Step 3
Router(config)# ip address address
mask
Step 4
Router(config)# end
Step 5
Router# show ip interface
Step 6
Router# copy running-config
startup-config
Use the no interface loopback 0 global configuration command to disable the loopback interface.

Monitoring OSPF

You can display specific statistics such as the contents of IP routing tables, caches, and databases.
Table 11-3
database privileged EXEC command options and for explanations of fields in the resulting display, refer
to the Cisco IOS IP and IP Routing Command Reference.
Table 11-3 Show IP OSPF Statistics Commands
Command
Router(config)# show ip ospf [ process-id ]
Router(config)# show ip ospf [ process-id ] database [router]
[ link-state-id ]
Router(config)# show ip ospf border-routes
Router(config)# show ip ospf interface [ interface-name ]
Router(config)# show ip ospf neighbor [ interface-name ]
[ neighbor-id ] detail
Router(config)# show ip ospf virtual-links
lists some of the privileged EXEC commands for displaying statistics. For more show ip ospf
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
Purpose
Enters global configuration mode.
Creates a loopback interface, and enters interface
configuration mode.
Assigns an IP address to this interface.
Returns to privileged EXEC mode.
Verifies your entries.
(Optional) Saves your entries in the configuration file.
Purpose
Displays general information about OSPF routing
processes.
Displays lists of information related to the OSPF
database.
Displays the internal OSPF routing ABR and
ASBR table entries.
Displays OSPF-related interface information.
Displays OSPF interface neighbor information.
Displays OSPF-related virtual links information.
Configuring OSPF
11-19