Users Guide

BGP 1377
Figure 38-3. Combining iBGP Routes
Address Aggregation
Dell EMC Networking BGP supports address aggregation. The network
administrator can configure up to 128 aggregate addresses. BGP compares
active prefixes in the local RIB to the set of aggregate addresses. To be
considered a match for an aggregate address, a prefix must be more specific
(i.e., have a longer prefix length) than the aggregate address. A prefix whose
prefix length equals the length of the aggregate address is not considered for
aggregation. If one or more prefixes fall within an aggregate, the aggregate is
considered active. A prefix must be used for forwarding to be considered for
inclusion in an aggregate address (unless it is a locally-originated prefix).
Aggregate addresses may overlap (for example, 10.1.0.0/16 and 10.0.0.0/8). A
prefix that matches overlapping aggregates is considered to match only the
aggregate with the longest mask. When an aggregate address becomes active
(that is, when the first contained route is matched to the aggregate), BGP