Cisco BGP-4 Command and Configuration Handbook

8-5 neighbor { ip-address peer- group - name } description text

Syntax Description:

• ip-address Neighbor's IP address.

• peer-group-name Name of the peer group. See section 8-19.

• text Line describing the neighbor (1 to 80 characters ).

Purpose: The description option performs a function that is similar to a comment in a software program. This function simply helps the reader determine the purpose of the code or, in the BGP case, the identification of the neighbor. Adding a neighbor description to a BGP configuration does not affect the operation of BGP. The description should convey useful information that can be quickly used to identify neighbors. For simple scenarios that have few neighbors, the description option has limited usefulness . For an ISP that has multiple neighbor relationships, however, you can use the description command to identify a neighbor without having to memorize its IP address.

Cisco IOS Software Release: 11.3

Configuration Example: Identifying a BGP Neighbor

Figure 8-7 shows an ISP and one of its neighbor connections. The ISP uses the description option to quickly identify the customers associated with each BGP connection.

Router A router bgp 65123 neighbor 10.1.1.2 remote-as 1 ___________________________________________________________________________ Router B router bgp 1 neighbor 10.1.1.1 remote-as 65123 neighbor 10.1.1.1 description ABC Company

Verification

Use the show ip bgp neighbors command to verify the description, as shown in the following output.

r3r1# show ip bgp neighbors BGP neighbor is 10.1.1.2, remote AS 1, external link Description: ABC Company Index 1, Offset 0, Mask 0x2 BGP version 4, remote router ID 10.1.1.2 BGP state = Established, table version = 4, up for 00:08:56 Last read 00:00:56, hold time is 180, keepalive interval is 60 seconds Minimum time between advertisement runs is 30 seconds Received 60 messages, 0 notifications, 0 in queue Sent 58 messages, 0 notifications, 0 in queue Prefix advertised 0, suppressed 0, withdrawn 0 Connections established 2; dropped 1 Last reset 00:09:27, due to User reset 3 accepted prefixes consume 96 bytes 0 history paths consume 0 bytes Connection state is ESTAB, I/O status: 1, unread input bytes: 0 Local host: 10.1.1.1, Local port: 11000 Foreign host: 10.1.1.2, Foreign port: 179

Troubleshooting

1. Verify that the BGP neighbors are in the Established state using the show ip bgp neighbors command.

   If the neighbor relationship is not in the Established state, see section 8-23.

2. If the description is not contained in the output from the show ip bgp neighbors command, the wrong neighbor IP address was used with the neighbor command containing the description.