This section provides information to configure BGP and configuration examples of common configuration tasks. The minimal BGP parameters that need to be configured are shown below.
An autonomous system number for the router.
A router ID. If a new or different router ID value is entered in the BGP context, then the new value takes precedence and overwrites the router-level router ID.
A BGP peer group.
A BGP neighbor with which to peer.
A BGP peer-AS that is associated with the above peer.
The BGP configuration commands have three primary configuration levels: bgp for global configurations, group name for BGP group configuration, and neighbor ip-address for BGP neighbor configuration. Within the different levels, many of the configuration commands are repeated. For the repeated commands, the command that is most specific to the neighboring router is in effect, that is, neighbor settings have precedence over group settings which have precedence over BGP global settings.
Following is an example configuration that includes the above parameters. The other parameters shown below are optional:
info
#--------------------------------------------------
echo "IP Configuration"
#--------------------------------------------------
...
autonomous-system 200
confederation 300 members 200 400 500 600
router-id 10.10.10.103
#--------------------------------------------------
...
#--------------------------------------------------
echo "BGP Configuration"
#--------------------------------------------------
bgp
graceful-restart
exit
cluster 0.0.0.100
export "direct2bgp"
router-id 10.0.0.12
group "To_AS_10000"
connect-retry 20
hold-time 90
keepalive 30
local-preference 100
remove-private
peer-as 10000
neighbor 10.0.0.8
description "To_Router B - EBGP Peer"
connect-retry 20
hold-time 90
keepalive 30
local-address 10.0.0.12
passive
preference 99
peer-as 10000
exit
exit
group "To_AS_30000"
connect-retry 20
hold-time 90
keepalive 30
local-preference 100
remove-private
peer-as 30000
neighbor 10.0.3.10
description "To_Router C - EBGP Peer"
connect-retry 20
hold-time 90
keepalive 30
peer-as 30000
exit
exit
group "To_AS_40000"
connect-retry 20
hold-time 30
keepalive 30
local-preference 100
peer-as 65206
neighbor 10.0.0.15
description "To_Router E - Sub Confederation AS 65205"
connect-retry 20
hold-time 90
keepalive 30
local-address 10.0.0.12
peer-as 65205
exit
exit
exit
#--------------------------------------------------
....
A:ALA-48>config>router#