Route Aggregation - Avaya 1000 Series Configuration Manual

Configuring BGP Features
18.1.6.0/24
All the routes above show the PATH information as 100 200 which means the routes were
originally originated from AS 200 and it is learned through AS 100.

Route Aggregation

Aggregation in BGP is used to summarize more specific routes into a single less specific route
so that the route table size is reduced or optimized.
Aggregate all the 18.1.1.0 to 18.1.7.0 routes in to one range 18.1.0.0/21 on Avaya1.
Avaya1/configure/router/bgp 100> aggregate_address 18.1.0.0
255.255.248.0
The above command aggregates all the routes 18.1.1.0 to 18.1.1.7.0 as 18.1.0.0/21.
View the bgp table of Avaya2 to see whether the aggregated route is announced by Avaya1
or not.
Avaya2> show ip bgp table
BGP route table, local router ID is 100.1.1.3 Status codes: * valid,> best, i -
internal Origin codes: i - IGP, e - EGP, ? - incomplete
Network
18.1.1.0/24
18.1.2.0/24
18.1.3.0/24
18.1.4.0/24
18.1.5.0/24
18.1.6.0/24
18.1.7.0/24
Entry 18.1.0.0/21 in Avaya2's bgp table shows that the aggregated route is advertised by
Avaya1. Note the PATH information for that route, it says 100. Even though the routes 18.1.1.0
to 18.1.7.0 were advertised originally by 3rdPartyRouter, since Avaya1 is aggregating it, the
source AS is 100 now.
Do a summary only on Avaya1.
Avaya1/configure/router/bgp 100>aggregate_address 18.1.0.0
255.255.248.0 summary_only
314 Avaya Secure Router 1000 Series Configuration Guide
20.1.1.1
Orig Next Hop Next Hop
20.1.1.1 20.1.1.1
20.1.1.1 20.1.1.1
20.1.1.1 20.1.1.1
20.1.1.1 20.1.1.1
20.1.1.1 20.1.1.1
20.1.1.1 20.1.1.1
20.1.1.1 20.1.1.1
20.1.1.1
Metric
100 200 ?
LocPrf Path
100 200 ?
100 200 ?
100 200 ?
100 i
100 200 ?
100 200 ?
100 200 ?
December 2010