activate

The activate command is new to IOS BGP configuration as part of the AF CLI enhancements. It's used to enable (or activate) support of the specified AF for a neighbor. This section discusses the old method used to enable an AF for a neighbor and then provides guidelines for using the new method.

Old Style

The activate command was not available in 12.0S. The neighbor was activated for IPv4 BGP automatically. However, if MBGP was enabled, the nlri keyword in the neighbor command was required:

Router(config-router)#neighbor 1.2.3.4 remote-as 10 nlri unicast multicast

If the nlri keyword was not specified, the router would exchange IPv4 prefixes only. If the nlri keyword was specified with the multicast option only, only the IPv4 multicast NLRI would be exchanged. This way you could activate only unicast, or only multicast, or both.

AF Style

To enable an AF for the neighbor, the activate command is used in BGP router or address-family configuration submode. The neighbors that are defined under the BGP router submode are automatically activated for IPv4. For all other AFs, the neighbors must be explicitly activated. To deactivate a neighbor for an AF, use the no form of the command. The following command syntax demonstrates how to enable neighbor 1.2.3.4 to support IPv4 multicast:

Router(config-router)#address-family ipv4 multicast
Router(config-router-af)# neighbor 1.2.3.4 activate