Concept Guide
R2(conf-router_bgp)# neighbor 2001::1 remote-as 10
R2(conf-router_bgp)# neighbor 2001::1 no shutdown
R2(conf-router_bgp)# address-family ipv4 multicast
R2(conf-router_bgp_af)# neighbor 20.20.20.1 activate
R2(conf-router_bgp_af)# exit
R2(conf-router_bgp)# address-family ipv6 unicast
R2(conf-router_bgpv6_af)# neighbor 20.20.20.1 activate
R2(conf-router_bgpv6_af)# neighbor 2001::1 activate
R2(conf-router_bgpv6_af)#exit
Following is the sample output for show ip bgp summary command.
R2#show ip bgp summary
BGP router identifier 2.2.2.2, local 200
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
2 neighbor(s) using 40960 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.1 10 10 20 0 0 0 00:06:11 0
2001::1 10 40 45 0 0 0 00:03:14 0
Following is the sample output of show ip bgp ipv4 multicast summary command.
R2# show ip bgp ipv4 multicast summary
BGP router identifier 2.2.2.2, local AS number 200
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
1 neighbor(s) using 24576 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.1 10 10 20 0 0 0 00:06:11 0
R2#
Following is the output of show ip bgp ipv6 unicast summary command for the above conguration example.
R2#show ip bgp ipv6 unicast summary
BGP router identifier 2.2.2.2, local AS number 200
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
2 neighbor(s) using 24576 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.1 10 10 20 0 0 0 00:06:11 0
2001::1 10 40 45 0 0 0 00:03:14 0
R2#
Congure IPv6 NH Automatically for IPv6 Prex
Advertised over IPv4 Neighbor
You can congure the system to pick the next hop IPv6 address dynamically for IPv6 prex advertised over an IPv4 neighbor congured
under IPv6 address family. If there is no IPv6 address congured on the local interface, the system uses the IPv4 mapped IPv6 address. If
there are multiple IPv6 addresses congured on the interface, the system uses the lowest IPv6 address congured on that interface. If the
conguration is already present and a new IPv6 address, which is lower than the lowest existing address, is assigned to one of the peer
interfaces, that address is not used as the NH until you ap the interface manually.
Figure 25. Congure IPv6 NH to advertise IPv6 prex over IPv4 neighbor
Border Gateway Protocol (BGP)
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