Filter
Top Products
446 CHAPTER 29: CONFIGURING OSPF
[RouterB] ospf enable
[RouterB] interface ethernet 0
[RouterB-Ethernet0] ip address 192.1.1.2 255.255.255.0
[RouterB-Ethernet0] ospf enable area 0
[RouterB-Ethernet0] ospf authentication-mode simple 3Com
3 Configure Router C:
[RouterC] router id 3.3.3.3
[RouterC] ospf enable
[RouterC-ospf] interface serial 0
[RouterC-Serial0] ip address 193.1.1.2 255.255.255.0
[RouterC-Serial0] ospf enable area 1
[RouterC-Serial0] ospf authentication-mode md5 3Com 11
Troubleshooting an
OSPF Configuration
You have configured OSPF as described previously, but router OSPF fails to run
normally.
Perform the following procedures:
1 Troubleshoot the local area: First check whether the protocol between the two
directly connected routers is running normally. If the peer state machine between
the two routers is in FULL status, it means the protocol is running normally. (Note
that on broadcast network and NBMA network, the peer state machine between
two DROther routers is not in FULL status but in 2 way status. DR, BDR and all
other routers are in FULL status).
Use the display ospf peer command to view:
[Router] display ospf peer
Interface: 202.38.160.1 Area: 0.0.0.2
Neighbors:
RouterID: 2.2.2.2 Address: 202.38.160.2
State:FULL Mode: None Priority: 0
DR: 202.38.160.1 BDR: 202.38.160.1
Last Hello: 14:04 Last Exchange: 0
Authentication Sequence: a51dac
View OSPF information on the interface with the display ospf interface
command.
■ Check whether the physical connection and low layer protocol are running
normally. If the opposite router cannot ping through the local router, it means
that the physical connection and lower layer protocol are faulty.
■ If the physical connection and lower layer protocol are normal, check the OSPF
parameters configured on the interface. The parameters must be the same as
those of the adjacent routers of this interface. The parameters include
hellointerval, deadinterval and authentication. The area-id must be the same
and the network segment and mask must be consistent (the network segment
and mask of point-to-point and virtual link can be different).
■ Check whether the deadinterval value is at least 4 times the hellointerval value
on the same interface.
■ If the network type is NBMA or point-to-multipoint, or the interface type is
manually modified to point-to-point, use command
ospf network-type p2p
to manually specify the peer. In addition, when two routers are connected in