Nortel Networks NN47200-503 manual Diagnosing neighbor state problems

188IP Routing Configuration and Management

Interface Nbr Router ID	Nbr IP Address	Pri	State	RetransQLen	Perm
--------- ---------------	---------------	---	---------	-----------	----
10.1.1.18 1.1.1.2	10.1.1.17	50	Full	0	Dyn
Total OSPF Neighbors: 1

show ip route

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Ip Route

========================================================================

DSTMASKNEXT COST VLAN PORT PROT TYPE PRF

------------------------------------------------------------------------

172.3.3.0	255.255.255.252	172.3.3.1	1	1000	---- C		DB	0
172.1.1.0	255.255.255.0	10.1.1.17	40	100	T#5	O	IB	25
10.1.1.16	255.255.255.252 10.1.1.18		1	100	---- C		DB	0
10.1.1.24	255.255.255.252 10.1.1.17		30	100	T#5	O	IB	25
10.1.1.20	255.255.255.252 10.1.1.17		20	100	T#5	O	IB	25
10.1.1.8	255.255.255.252 10.1.1.17		20	100	T#5	O	IB	25
10.1.1.0	255.255.255.252	10.1.1.17	40	100	T#5	O	IB	25
0.0.0.0	0.0.0.0	10.1.1.17	11	100	T#5	O	IB	25
Total Routes:	8

------------------------------------------------------------------------

TYPE Legend: I=Indirect Route, D=Direct Route, A=Alternative Route, B=Best Route,E=Ecmp Route, U=Unresolved Route, N=Not in HW

Diagnosing neighbor state problems

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 lists the states a router can go through during the process of forming an adjacency.

OSPF neighbor states

Step	State	Description
1	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.
2	Attempt	On an NBMA interface, this state occurs when
		the router attempts to send unicast hellos to any
		configured interfaces. The Nortel Ethernet Routing
		Switch 5500 Series does not support NBMA type.

Nortel Ethernet Routing Switch 5500 Series

Configuration-IP Routing Protocols

NN47200-503 03.01 Standard

5.127 August 2007

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