Using the appearance ip ospf acquaintance Command
The appearance ip ospf acquaintance command is absolutely advantageous because it summarizes the pertinent
OSPF advice apropos neighbors and the adjacency state. If a DR or BDR exists, that
information will additionally be displayed. Here’s a sample:
Corp#sh ip ospf neighbor
Neighbor ID Pri Accompaniment Dead Time Abode Interface
10.1.11.1 0 FULL/ - 00:00:37 10.1.5.2 Serial0/2/0
10.1.9.1 0 FULL/ - 00:00:34 10.1.4.2 Serial0/1/0
10.1.7.1 0 FULL/ - 00:00:38 10.1.3.2 Serial0/0/1
10.1.7.1 0 FULL/ - 00:00:34 10.1.2.2 Serial0/0/0
This is an important command to accept because it’s acutely advantageous in production
networks! Here are the R3 and 871W routers’ outputs:
R3#sh ip ospf neighbor
Neighbor ID Pri Accompaniment Dead Time Abode Interface
10.1.5.1 0 FULL/ - 00:00:39 10.1.5.1 Serial0/0/1
10.1.11.2 1 FULL/BDR 00:00:31 10.1.11.2 FastEthernet0/1
871W#sh ip ospf nei
Neighbor ID Pri Accompaniment Dead Time Abode Interface
10.1.11.1 1 FULL/DR 00:00:30 10.1.11.1 Vlan1
Since there’s an Ethernet articulation (broadcast multiaccess) on the Corp router, there’s activity to
be an acclamation to actuate which router will be the appointed router and which router will
be the nondesignated router. You can see that the 871W became the baptize router, and it
won because it had the accomplished IP abode on the network. You can change this, but that’s the
default.
The acumen that the Corp access to R1, R2, and R3 don’t accept a DR or BDR listed
in the achievement is that by absence elections don’t appear on point-to-point links. But you can see
that the Corp router is absolutely adjoining to all three routers (and on both access to R1) from
its output.