Administrator Guide

BGP address family model
Dell EMC Networking OS supports BGP address family identier (AFI) with MBGP to provide scalability for multiple AFI and subsequent
address family identier (SAFI) congurations. MBGP carries routing information for address families (IPv4 and IPv6) of multiple network-
layer protocols. Each address family has a separated BGP database, so that you can congure BGP policy based on address family.
Implementing BGP global and address family
Implementing BGP is splitted as global and address family conguration.
BGP conguration command levels are grouped as high level and address family conguration. All independent commands are grouped at
the beginning of the conguration and followed by separate sub commands specic to each address family.
Following is the order of BGP conguration:
• Global conguration — General conguration that is applied to BGP. For example, conguring BGP timer, Adding additional BGP paths,
etc.
• Address family conguration — Congurations that are applied to a specic address family.
The BGP address family model consists of three address families such as IPv4 unicast, IPv4 multicast, and IPv6 unicast. The default
address family is IPv4 unicast. The neighbors congured under CONFIGURATION-ROUTER-BGP mode is considered to be IPv4 unicast
neighbor. To congure a neighbor for IPv4 multicast or IPv6 unicast, you have to explicity activate the neighbor in the respective address
family conguration, as shown the following example conguration.
Example of BGP conguration command levels
Following is an example conguration, which explains the neighbor conguration for all the address families.
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)#neighbor 2001::1 remote-as 200
DellEMC(conf-router_bgp)#neighbor 2001::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
DellEMC(conf-router_bgp)#address-family ipv6 unicast
DellEMC(conf-router_bgpv6_af)#neighbor 2001::1 activate
DellEMC(conf-router_bgpv6_af)#exit
BGP global conguration default values
By default, BGP is disabled. The following table displays the default values for BGP on Dell EMC Networking OS.
Table 9. BGP Default Values
Item Default
BGP Neighbor Adjacency changes All BGP neighbor changes are logged.
Fast External Fallover feature Disabled
Graceful Restart feature Disabled
Local preference 100
MED 0
Border Gateway Protocol (BGP) 183