By default, a device advertises
individual routes for all networks. To minimize the size of the routing table, you can
aggregate the routes in a range of networks into one IPv4 prefix.
About this task
You can aggregate BGP4 routes into one network prefix, for example, 10.1.1.1/32.
This single prefix is advertised to BGP4 neighbors instead of the individual BGP routes
in the routing table that are within the specified range.
Procedure
-
Access global configuration
mode.
device# configure terminal
-
Access BGP configuration mode.
device(config)# router bgp
-
Access BGP address family IPv4
unicast configuration mode.
device(config-bgp-router)# address-family ipv4 unicast
-
Specify the network prefix into
which routes are to be aggregated.
device(config-bgp-ipv4u)# aggregate-address 10.1.1.1/32
Example
The following example summarizes the
commands in this procedure.
device# configure terminal
device(config)# router bgp
device(config-bgp-router)# address-family ipv4 unicast
device(config-bgp-ipv4u)# aggregate-address 10.1.1.1/32
