The default ipv4-unicast command enables the IPv4 unicast address family of all neighbors.
The undo default ipv4-unicast command disables the IPv4 unicast address family of all neighbors.
By default, IPv4 unicast address family is enabled.
Usage Scenario
If the IPv4 unicast address family needs to be enabled by default for created BGP peers, the default ipv4-unicast command can be used to configure the default address family of BGP to the IPv4 unicast address family.
If the IPv4 unicast address family does not need to be enabled by default for created BGP peers, the undo default ipv4-unicast command can be used to disable the IPv4 unicast address family for all peers.
Configuration Impact
After the default ipv4-unicast command is run, the IPv4 unicast address family is enabled by default for created BGP peers.
Precautions
After the undo default ipv4-unicast command is run, the peer enable command needs to be run if the created BGP peer needs to be enabled with the IPv4 unicast address family.