Configuring BGP
Configuring Advanced BGP Features
IPC-315
Cisco IOS IP Configuration Guide
BGP Conditional Advertisement Configuration Task List
See the following section for configuration tasks for the BGP Conditional Advertisement feature. Each
task in the list indicates if the task is optional or required.
•Configure the route-maps that will be used in conjunction with the advertise-map and the
non-exist-map. This step may include the configuration of access-lists or prefix-lists. (Required)
•Configure the router to run BGP. (Required)
•Configure the advertise-map and the non-exist-map with the neighbor advertise-map
non-exist-map router configuration command. (Required)
•Verify that the BGP Condition Advertisement feature has been configured with the show ip bgp
neighbor command. (Optional)
Conditional Advertisement of a Set of Routes
To conditionally advertise a set of routes, use the following commands beginning in router configuration
mode:
See the “BGP Conditional Advertisement Configuration Examples” section at the end of this chapter for
an example configuration of BGP conditional advertisement.
Verifying BGP Conditional Advertisement
To verify that the BGP Condition Advertisement feature has been configured, use the show ip bgp
neighbor command. The show ip bgp neighbor EXEC command will show the status of the BGP
Conditional Advertisement feature as initialized or uninitialized. The following example shows output
from the show ip bgp neighbor EXEC command:
router# show ip bgp neigbor 172.16.1.1
BGP neighbor is 172.16.1.1, remote AS 65200, internal link
Description:link to boston as 65200
BGP version 4, remote router ID 10.1.1.1
BGP state = Established, up for 01:04:30
Last read 00:00:30, hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
Route refresh:advertised and received
Address family IPv4 Unicast:advertised and received
Received 83 messages, 0 notifications, 0 in queue
Sent 78 messages, 0 notifications, 0 in queue
Route refresh request:received 0, sent 0
Minimum time between advertisement runs is 5 seconds
For address family:IPv4 Unicast
BGP table version 18, neighbor version 18
Index 2, Offset 0, Mask 0x4
Command Purpose
Step1 Router(config)# router bgp as-number Configures the router to run a BGP process.
Step2 Router(config-router)# neighbor ip-address remote-as
as-number
Specifies the peer that should receiveconditional
advertisement for a given set routes.
Step3 Router(config-router)# neighbor ip-address adver-
tise-map map1 non-exist-map map2
Configures the advertise-map and non-exist map
for the BGP Conditional Advertisement feature.