Ospf Neighbor State Problems - Avaya 8800 Troubleshooting Manual

Unicast routing troubleshooting

OSPF neighbor state problems

You can view status of all the OSPF neighbors and their current adjacency state to determine
if problems occurred during the router initial startup sequence.
Problems with OSPF occur most often during the initial startup, when the router cannot form
adjacencies with other routers and the state is stuck in the Init or ExStart/Exchange state.
To view the current state of all OSPF neighbors and their current state of adjacency,
use the following command in the CLI or ACLI:
show ip ospf neighbor
Job aid: OSPF neighbor states
At initial startup, routers transmit Hello packets in an attempt to find other OSPF routers with
which form adjacencies. After the Hello packets are received, the routers perform an
initialization process, which causes the routers to transition through various states before the
adjacency is established.
The following table describes the various states a router can be in when forming an
adjacency.
Table 19: OSPF neighbor states
Step
1
2
3
4
5
6
7
8
360 Troubleshooting
State
Down Indicates that a neighbor was configured manually, but the
router did not received any information from the other router.
This state can occur only on NBMA interfaces.
Attempt On an NBMA interface, this state occurs when the router
attempts to send unicast Hellos to any configured
interfaces.
Init The router received a general Hello packet (without its
Router ID) from another router.
2-Way The router received a Hello directed to it from another router.
(The Hello contains its Router ID.)
ExStart Indicates the start of the Master/Slave election process.
Exchange Indicates the link state database (LSDB) is exchanged
Loading Indicates the processing state of the LSDB for input into the
routing table. The router can request LSA for missing or
corrupt routes.
Full Indicates the normal full adjacency state.
Comments? infodev@avaya.com
Description
July 2013