Service Manual

network 192.168.128.0/24
neighbor AAA peer-group
neighbor AAA no shutdown
neighbor BBB peer-group
neighbor BBB no shutdown
neighbor 192.168.128.1 remote-as 99
neighbor 192.168.128.1 peer-group CCC
neighbor 192.168.128.1 update-source Loopback 0
neighbor 192.168.128.1 no shutdown
neighbor 192.168.128.3 remote-as 100
neighbor 192.168.128.3 peer-group BBB
neighbor 192.168.128.3 update-source Loopback 0
neighbor 192.168.128.3 no shutdown
R2(conf-router_bgp)#end
R2#
R2#show ip bgp summary
BGP router identifier 192.168.128.2, local AS number 99
BGP table version is 2, main routing table version 2
1 network entrie(s) using 132 bytes of memory
3 paths using 204 bytes of memory
BGP-RIB over all using 207 bytes of memory
2 BGP path attribute entrie(s) using 128 bytes of memory
2 BGP AS-PATH entrie(s) using 90 bytes of memory
2 neighbor(s) using 9216 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
192.168.128.1 99 140 136 2 0 (0) 00:11:24 1
192.168.128.3 100 138 140 2 0 (0) 00:18:31 1
Example of Enabling Peer Groups (Router 3)
R3#conf
R3(conf)#router bgp 100
R3(conf-router_bgp)# neighbor AAA peer-group
R3(conf-router_bgp)# neighbor AAA no shutdown
R3(conf-router_bgp)# neighbor CCC peer-group
R3(conf-router_bgp)# neighbor CCC no shutdown
R3(conf-router_bgp)# neighbor 192.168.128.2 peer-group BBB
R3(conf-router_bgp)# neighbor 192.168.128.2 no shutdown
R3(conf-router_bgp)# neighbor 192.168.128.1 peer-group BBB
R3(conf-router_bgp)# neighbor 192.168.128.1 no shutdown
R3(conf-router_bgp)#
R3(conf-router_bgp)#end
R3#show ip bgp summary
BGP router identifier 192.168.128.3, local AS number 100
BGP table version is 1, main routing table version 1
1 network entrie(s) using 132 bytes of memory
3 paths using 204 bytes of memory
BGP-RIB over all using 207 bytes of memory
2 BGP path attribute entrie(s) using 128 bytes of memory
2 BGP AS-PATH entrie(s) using 90 bytes of memory
2 neighbor(s) using 9216 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
192.168.128.1 99 93 99 1 0 (0) 00:00:15 1
192.168.128.2 99 122 120 1 0 (0) 00:00:11 1
Advanced BGP configuration tasks
The following sections describe how to configure the advanced (optional) BGP configuration tasks.
Route-refresh and Soft-reconfiguration
BGP soft-reconfiguration allows for faster and easier route changing.
Changing routing policies typically requires a reset of BGP sessions (the TCP connection) for the policies to take effect. Such
resets cause undue interruption to traffic due to hard reset of the BGP cache and the time it takes to re-establish the session.
BGP soft-reconfiguration allows for policies to be applied to a session without clearing the BGP Session. Soft-reconfiguration
can be done on a per-neighbor basis and can either be inbound or outbound.
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Border Gateway Protocol (BGP)