Aggregation Support in the NSFNET Policy-Based Routing Database

This document describes plans for support of route aggregation, as specified in the descriptions of Classless Inter-Domain Routing (CIDR) [1] and the BGP-4 protocol [2], by the NSFNET Backbone Network Service. Mechanisms for exchange of route aggregates between the backbone service and regional/midlevel networks are specified. Additionally, the memo proposes the implementation of an Aggregate Registry which can be used by network service providers to share information about the use of aggregation. Finally, the operational impact of incorporating CIDR and aggregation is considered, including an analysis of how routing table size will be affected. This impact analysis will be used to modify the deployment plan, if necessary, to maximize operational stability.