Troubleshooting guide

Troubleshooting OSPF
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Introduction
This chapter provides troubleshooting solutions to some common Open Shortest Path
First (OSPF) routing protocol problems:
• Handling OSPF-designated Interface Problems
• Handling Router Neighbor Misconfigurations
• Resolving Missing Routes in Routing Table
Handling OSPF-designated Interface Problems
OSPF uses an IP address on the BSR as its router ID. Therefore, to configure the
OSPF protocol on the BSR, at least one active interface needs to be configured with
an IP address.
1. To discover if there is no active OSPF interface with an IP address, use the router
ospf command in Global Configuration mode, as shown in the following
example:
RDN(config)#router ospf
The BSR returns the following error:
RDN(config)#OSPF: Could not allocate router id
2. To ensure that a router interface is configured with an IP address and is enabled,
use the show ip interfaces command in Privileged EXEC mode.
3. If there is no active interface with an IP address, configure an interface with the ip
address command in Router Configuration mode. If necessary, use the no
shutdown command in Router Configuration mode to activate an interface.
For example, to enter Router Configuration mode from Global Configuration
mode, assign an IP address to ethernet 7/0, and perform a no shutdown command
on the interface, enter the following commands:
RDN(config)#interface ethernet 7/0
RDN(config-if)#ip address 10.1.1.5 255.255.255.252
RDN(config-if)#no shutdown