To pass the BSCI exam, earn your CCNP certification, and become an outstanding networker, you've got to master the many details of BGP - and trust me, there are a lot of details to master! Before you get into the more advanced features of BGP, you should have the fundamentals down cold, and one of those fundamentals is knowing the BGP adjacency states. This will allow you to successfully analyze and troubleshoot BGP peer relationships.

In the following example, a BGP peering is being created between R1 and R3. R1(config-router)#neighbor 172.12.123.3 remote-as 200

BGP speakers do not have to be in the same AS to become peers. To verify that the remote BGP speaker has become a peer, run show ip bgp neighbor.

R1#show ip bgp neighbor

BGP neighbor is 172.12.123.3, remote AS 200, external link

BGP version 4, remote router ID 0.0.0.0

BGP state = Active

Last read 00:01:39, hold time is 180, keepalive interval is 60 seconds

Received 0 messages, 0 notifications, 0 in queue

Sent 0 messages, 0 notifications, 0 in queue

Route refresh request: received 0, sent 0

Default minimum time between advertisement runs is 30 seconds

The output here can be a little misleading the first time you read it. The first highlighted line shows 172.12.123.3 is a BGP neighbor, is located in AS 200, and is an external link, indicating that the neighbor is in another AS entirely. The second highlighted line shows the BGP state as Active. This sounds great, but it actually means that a BGP peer connection does not yet exist with the prospective neighbor. Before we continue with this example, let