The complete 6NET IPv6 address range could be aggregated to ‘2001:0798::/40’. However, due to the aggressive filtering policies on the IPv6 Internet (see RFC 2772 [RFC2772]), initially the address range was aggregated to ‘2001:0798::/35’. To do this type of aggregation in a controllable way, some NLRI filtering was required. To enable the aggregation, 3 basic steps were required:

1. Configure static IPv6 route for ‘2001:0798::/35’ to the null0 interface
2. Redistribute the static summary route to the IPv6 BGP table (this required NLRI filtering in order to redistribute only the summary prefix)
3. Use BGP NLRI filtering to the iBGP peers to exclude the summary prefix from being exchanged.