3Com Switch 7750 Configuration Guide Guide

Troubleshooting OSPF Configuration 311
[SwitchC-Vlan-interface1] quit
[SwitchC] interface Vlan-interface 2
[SwitchC-Vlan-interface2] ip address 197.1.1.1 255.255.255.0
[SwitchC-Vlan-interface2] quit
[SwitchC] router id 3.3.3.3
[SwitchC] ospf
[SwitchC-ospf-1] area 1
[SwitchC-ospf-1-area-0.0.0.1] network 197.1.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.1] quit
[SwitchC-ospf-1-area-0.0.0.1] vlink-peer 2.2.2.2
[SwitchC-ospf-1] area 2
[SwitchC-ospf-1-area-0.0.0.2] network 152.1.1.0 0.0.0.255
Troubleshooting OSPF
Configuration
Symptom 1: OSPF has been configured in accordance with the above-mentioned
steps, but OSPF does not run normally on the switch.
Solution: Perform the following procedure.
Local fault removal: Firstly, check whether the protocol works normally between
two directly connected routers. The normal sign is that the peer state machine
between the two routers reaches the FULL state. Note: On a broadcast or NBMA
network, if the interfaces between two routers are in DROther state, the peer state
machine between the two routers are in 2-way state, instead of FULL state. The
peer state machine between DR/BDR and all the other routers is in FULL state.
■ Use the display ospf peer command to view peers.
■ Use the display ospf interface command to view the OSPF information on an
interface.
■ Check whether the physical connection is correct and the lower layer protocol
operates normally. You can use the ping command to test. If the local router
cannot ping through the peer router, it indicates that faults exist on the
physical link and the lower level protocol.
■ If the physical connection and the lower layer protocol are normal, check the
OSPF parameters configured on the interface. Verify that these parameter
configurations are consistent with those on the peer interface. The area IDs
must be the same, and the network segments and the masks must also be
consistent (p2p or virtually linked segments can have different segments and
masks).
■ Ensure that the dead timer value is at least four times of the hello timer value
on the same interface.
■ If the network type is NBMA, you must use the peer ip-address command to
manually specify a peer.
■ If the network type is broadcast or NBMA, ensure that there is at least one
interface with a priority greater than zero.
■ If an area is set to a stub area, ensure that the area is set to a stub area for all
the routers connected to this area.
■ Ensure that the interface types of two neighboring routers are consistent.
■ If two or more areas are configured, ensure that at least one area is configured
as the backbone area; that is, the area ID of an area is 0.