Cabletron Systems 9032578-05 manual Creating an Aggregate Route

Chapter 13: Routing Policy Configuration Guide

Creating an Aggregate Route

Route aggregation is a method of generating a more general route, given the presence of a specific route. The routing process does not perform any aggregation unless explicitly requested. Aggregate-routes can be constructed from one or more of the following building blocks:

•Aggregate-Destination - This component specifies the aggregate/summarized route. It also specifies the attributes associated with the aggregate route. The preference to be associated with an aggregate route can be specified using this component.

•Aggregate-Source - This component specifies the source of the routes contributing to an aggregate/summarized route. It can also specify the preference to be associated with the contributing routes from this source. The routes contributing to an aggregate can be identified by their associated attributes, including protocol type, tag associated with a route, and so on.

•Route Filter - This component provides the means to define a filter for the routes to be aggregated or summarized. Routes that match a filter are considered as eligible for aggregation. This can be done using one of two methods:

–Creating a route-filter and associating an identifier with it. A route-filter has several network specifications associated with it. Every route is checked against the set of network specifications associated with all route-filters to determine its eligibility for aggregation. The identifier associated with a route-filter is used in the ip-router policy aggr-gencommand.

–Specifying the networks as needed in the ip-router policy aggr-gencommand.

•If you want to create a complex route-filter, and you intend to use that route-filter in several aggregates, then the first method is recommended. It you do not have complex filter requirements, then use the second method.

After you create one or more building blocks, they are tied together by the ip-router policy aggr-gencommand.

To create aggregates, enter the following command in Configure mode:

Create an aggregate route.

ip-router policy aggr-gen destination <aggr-dest-id>[source <aggr-src-id>[filter <filter-id>[network <ipAddr-mask>[exactrefinesbetween <low-high>] [preference <number>restrict]]]]

The <aggr-dest-id>is the identifier of the aggregate-destination that specifies the aggregate/summarized route.

The <aggr-src-id>is the identifier of the aggregate-source that contributes to an aggregate route. If an aggregate has more than one aggregate-source, then the ip-router policy aggr- gen destination <aggr-dest-id>command should be repeated for each <aggr-src-id>.

SmartSwitch Router User Reference Manual 179