BGP Conditional Advertisements - Advertise Maps
Share this page:This is a pretty complex BGP issue because you really need to know the BGP philosophy and maybe even have some basic experience in programming. The trick is to change the behavior of the BGP advertisements depending on the routes that are being learned.
router bgp 65545
** neighbor 172.25.13.3 advertise-map ADV_ROUTE_MAP non-exist-map CONDITION_ROUTE_MAP**
Intuitively we can see that the ADV_ROUTE_MAP is the route map that defines the routes that will be broadcast, in this case if the conditions defined in the route-map CONDITION_ROUTE_MAP is NOT satisfied, meaning - if the prefixes are NOT in the table.