Viewing OSPF neighbor information

Syntax:


show ip ospf neighbor [ip-addr]

To display OSPF information for all neighbors, enter show ip ospf neighbor at any CLI level.

[ip-addr] can be specified to retrieve detailed information for the specific neighbor only. This is the IP address of the neighbor, not the router ID.

Output for the show ip ospf neighbor command

OSPF Neighbor Information

                                                         Rxmt         Helper
  Router ID       Pri IP Address     NbIfState State     QLen  Events Status
  --------------- --- -------------- --------- --------- ----- ------ ------
  10.0.8.34       1   10.3.18.34     DR        FULL      0     6      none
  10.3.53.38      1   10.3.53.38     DR        FULL      0     6      none

This display shows the following information.

CLI display of OSPF neighbor information

Field

Description

Router ID

The router ID of the neighbor.

Pri

The OSPF priority of the neighbor. The priority is used during election of the DR and BDR.

IP Address

The IP address of this routing switch's interface with the neighbor.

NbIfState

The neighbor interface state. The possible values are:
DR

This neighbor is the elected designated router for the interface.

BDR

This neighbor is the elected backup designated router for the interface.

blank

This neighbor is neither the DR or the BDR for the interface.

State

The state of the conversation (the adjacency) between your routing switch and the neighbor. The possible values are:
INIT

A Hello packet has recently been seen from the neighbor. However, bidirectional communication has not yet been established with the neighbor. (The switch itself did not appear in the neighbor's hello packet.) All neighbors in this state (or higher) are listed in the hello packets sent from the associated interface.

2WAY

Communication between the two routers is bidirectional. This is the most advanced state before beginning adjacency establishment. The DR and BDR are selected from the set of neighbors in the 2Way state or greater.

EXSTART

The first step in creating an adjacency between the two neighboring routers. The goal of this step is to decide which router is the master and to decide upon the initial database description (DD) sequence number. Neighbor conversations in this state or greater are called adjacencies.

EXCHANGE

The switch is describing its entire link state database by sending DD packets to the neighbor. Each DD packet has a DD sequence number and is explicitly acknowledged. Only one DD packet can be outstanding at any time. In this state, link-state request packets can also be sent asking for the neighbor's more recent advertisements. All adjacencies in exchange state or greater are used by the flooding procedure. In fact, these adjacencies are fully capable of transmitting and receiving all types of OSPF routing protocol packets.

LOADING

Link-state request packets are sent to the neighbor asking for the more recent advertisements that have been discovered (but not yet received) in the exchange state.

FULL

The neighboring routers are fully adjacent. These adjacencies will now appear in router links and network link advertisements.

Rxmt QLen

Remote transmit queue length—The number of LSAs that the routing switch has sent to this neighbor and for which the routing switch is awaiting acknowledgements.

Events

The number of times the neighbor's state has changed.

Helper Status

Whether the neighboring router is helping the OSPF router. The possible values are:

Helper

The neighbor is helping.

None

The neighbor is not helping.

Helper Age

Amount of time the neighboring router is helping. This time can range from 1 to 1800 seconds with a default time of 120 seconds. Helper Age is 0 when the router is not helping.