Aggregating routes advertised to BGP neighbors

A device can be configured to aggregate routes in a range of networks into a single IP prefix.
  1. Enter the configure terminal command to access global configuration mode. 
    device# configure terminal
  2. Enter the router bgp command to enable BGP routing. 
    device(config)# router bgp
  3. Enter the aggregate-address command to aggregate the routes from a range of networks into a single network prefix. 
    device(config-bgp-router)# aggregate-address 10.1.1.1/32

The following example enables a BGP4 device to advertise the default route and send the default route to a specified neighbor. 

device# configure terminal
device(config)# router bgp
device(config-bgp-router)# aggregate-address 10.1.1.1/32
Parent topic: BGP4