R2(config-router)#aggregate-address 188.8.131.52 255.255.255.0 ? advertise-map Set condition to advertise attribute
as-set Generate AS set path information
attribute-map Set attributes of aggregate nlri Nlri aggregate applies to route-map Set parameters of aggregate summary-only Filter more specific routes from updates suppress-map Conditionally filter more specific routes from updates <cr>
You could presumably use summary-only to filter all the more specific routes, however what if you wanted to suppress only a selected few of the more specific routes and advertise the rest of the specific routes along with the aggregate? This is where "suppress-map" or "advertise-map" comes to the rescue If you only had a few specific routes to advertise but a lot of specific routes to suppress out of an aggregate then you would use the "advertise-map" to advertise just what you want. However, if you only had a few specific routes to suppress but more specific prefixes to advertise then you would use a "suppress-map" to suppress what you want and advertise the rest. See below for "suppress-map" in action.