Allied Telesis VERSION 5.4.3-2.6 manual BGP and BGP4+ Aggregate Addresses

BGP and BGP4+ Introduction

BGP and BGP4+ Aggregate Addresses

CIDR (Classless Inter-Domain Routing) enables you to create aggregate routes to minimize the size of routing tables. CIDR is a routing method supported by BGP and BGP4+ that is based on route aggregation. CIDR allows a router to group routes together to minimize the amount of routing information carried. Several IP networks appear as a single network to networks outside of those grouped together

You can configure aggregate routes in BGP or BGP4+ either by redistributing an aggregate route into BGP or BGP4+ or by using the BGP and BGP4+ Aggregation feature. An aggregate address is added to the BGP table if at least one entry is in the BGP table.

To create an IPv4 aggregate address in the BGP routing table, use the following command in the Router Configuration mode:

awplus(config-router)#

aggregate-address<ip-addr/m>This command creates an aggregate IPv4 route entry in the BGP {summary-onlyas-set}routing table. This entry will cause BGP to advertise IPv4

summary addresses only, if the summary-onlyparameter is applied. This entry will cause BGP to generate autonomous system set path information, if the the as-setparameter is applied.

To create an IPv6 aggregate address in the BGP4+ routing table, use the following command in the Address Family Configuration mode:

awplus(config-router-af)#

aggregate-address<ipv6-addr/This command creates an aggregate IPv6 route entry in the prefix-length>{summary-onlyBGP4+ routing table. This entry will cause BGP4+ to advertise

as-set}IPv6 summary addresses only, if the summary-onlyparameter is applied. This entry will cause BGP4+ to generate autonomous system set path information, if the the as-setparameter is applied.

How to enable and disable Automatic

Summarization

When a subnet is redistributed from an IGP to BGP, network routes are added to routing tables. By default, automatic summarization is disabled. To enable automatic network number summarization, use the following command in Router Configuration mode:

awplus(config-router)#

auto-summaryThis command enables automatic network summarization.

To disable automatic network number summarization, use the following command in Router Configuration mode:

awplus(config-router)#

no auto-summaryThis command disables automatic network summarization.

	Software Reference Supplement for SwitchBlade® x8112, x908, x900 and x610 Series Switches
1.28	AlliedWare PlusTM Operating System - Software Version 5.4.3-2.6	C613-50032-01 REV D