EIGRP Route Summarisation

To scale an EIGRP system effectively, it requires summarisation. EIGRP can summarise network prefixes on an interface basis.

Prefixes contained within the summarisation are suppressed with the summary route being advertised instead, although the summary route is only advertised if a suppressed prefix is valid within the summary route.

Route summarisation also creates a query boundary, shrinking the query domain when a route goes active.