Concept Guide

Conguring a BGP peer
To congure a BGP neighbor or peer, you must provide the IP address and the AS number of each neighbor since BGP does not discover
the neighbor or peer. Neighbors that are present with the same AS communicate using IBGP while the neighbors that are present in
dierent AS communicate using EBGP. To allow the neighbor to establish a BGP session, you have to enable the neighbor by providing
neighbor no shutdown command. To congure BGP between two peers, use the following commands.
Following are the steps to congure a BGP peer. The following example conguration demonstrates how the congure a neighbor and IPv4
multicast address family. The default is IPv4 unicast address family.
• Enter the router conguration mode and the AS number.
CONFIG mode
router bgp as-number
• Add the IP address of the neighbor for the specied autonomous system.
CONFIG-ROUTER-BGP mode
neighbor {ip-address | ipv6–address | peer-group-name} remote-as as-number
• Enable the neighbor.
CONFIG-ROUTERBGP mode
neighbor ip-address | ipv6-address | peer-group-name no shutdown
• Specify the IPv4 address family conguration.
CONFIG-ROUTER-BGP mode
address-family ipv4 [multicast | vrf vrf-name]
multicast — Species the IPv4 multicast address family.
vrf vrf-name — Species the name of VRF instance associated with the IPv4 address-family conguration.
• Enable the neighbor to exchange prexes for IPv4 unicast address family.
CONFIG-ROUTER-BGP-AF (Address Family) mode
neighbor {ip-address | ipv6–address | peer-group-name} activate
NOTE
: Neighbors have to be activated using neighbor activate command in the respective address family. To
exchange other address prex types (IPv4 multicast or IPv6 unicast), the neighbors must be activated under the
respective address family conguration such as address-family ipv4 multicast (for IPv4 multicast)
and
address-family ipv6 unicast(for IPv6).
Example of conguring BGP Peers
DellEMC(conf)# router bgp 10
DellEMC(conf-router_bgp)# neighbor 20.20.20.1 remote-as 200
DellEMC(conf-router_bgp)# neighbor 20.20.20.1 no shutdown
DellEMC(conf-router_bgp)# address-family ipv4 multicast
DellEMC(conf-router_bgp_af)# neighbor 20.20.20.1 activate
DellEMC(conf-router_bgp_af)# exit
Following is the sample output of show ip bgp ipv4 multicast summary command.
DellEMC# show ip bgp ipv4 multicast summary
BGP router identifier 1.1.1.1, local AS number 10
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
1 neighbor(s) using 8192 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.1 200 0 0 0 0 0 00:00:00 0
DellEMC#
Border Gateway Protocol (BGP)
205