Ospf Neighbor States - Avaya 8600 Engineering

7. OSPF Neighbor States

Upon initial startup, routers will attempt to find and form adjacencies with other OSPF routers via Hello
packets. Once these are received the routers perform some handshaking before adjacency is
established. The following table describes the various states of forming an adjacency.
Step State
1 Down
2 Attempt
3 Init
4 2-Way
5 ExStart
6 Exchange
7 Loading
8 Full
7.1.1 Troubleshooting Neighbor States
The following command will show all the neighbors and the current state of adjacency.
ERS-8610:6# show ip ospf neighbors
================================================================================
================================================================================
INTERFACE NBRROUTERID
-------------------------------------------------------------------------------------------------
-----------------------
10.1.1.22 1.1.1.1
Dynamic
10.1.1.17 1.1.1.5
Dynamic
10.1.1.9 1.1.1.4
Dynamic
Total ospf neighbors: 3
November 2010
Description
This is the initial OSPF neighbor state. It means a router has not received
any information (hellos) from its neighbor even if it can still send hellos to its
neighbor. This state can occur for NBMA or Point-to-Multipoint neighbors.
During a full adjacency state, if a router does not receive hello packets from
a neighbor within the Router Dead Interval time, then the neighbor state
changes from Full to Down. The default Dead Interval time is 4 x Hello
Interval, which by default is 40 seconds. This state does not occur on
Broadcast networks, which is initially in an Init state.
Also on NBMA interfaces, this state occurs when the router attempts to send
unicast hellos to any configured interfaces.
Router has received a general Hello packet (without its Router ID) from
another router.
Router received a Hello directed to it from another router. (Hello contains its
Router ID).
Master/Slave election process.
Link State Database is exchanged
Processing of the LSDB for input into the routing table. Router may request
LSA for missing or corrupt routes.
Normal full adjacency state.
Ospf Neighbors
NBRIPADDR PRIO_STATE
10.1.1.21
10.1.1.18
10.1.1.10
ERS 8600 / 8800 OSPF Technical Configuration Guide
avaya.com
RTXQLEN PERMANENCE
100 Full 0
0 Full
1 Full
0
0
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