[cisco-bba] PPPoE: Install route to IPv6 Peer Address on CPE

[Gary T. Giesen]

I've an issue which I hope someone has come across and solved.

We are in the process of implementing IPv6 for our DSL customers (PPPoE). A
very large number of these customers have BGP sessions to use, because the
DSL circuit is either primary or backup for another circuit.

Typically how we've done this with IPv4 is to configure a BGP session from
the customer's dialer to a lookback on the LNS (which also happened to be
the "unnumbered" address for the Virtual Template). As such, the CPE
(typically Cisco) would have a route for the PPP peer address installed in
the routing table, so they would know how to reach the BGP neighbor (and
vice-versa).

Under IPv6, we're assigning the clients static addresses with SLAAC using a
combination of Framed-IPv6-Prefix and Framed-Interface-Id. The LNS installed
a route for the /64 (which is adequate) and there's no issue there. However,
the CPE does not install a route for the IPv6, and as such does not know how
to reach the BGP peer to establish the session.

The workaround has been to configure the CPE with static routes pointing out
the Dialer interface for the various /128's for the loopbacks of all the
LNSes.  This is a bit hackish, and I'm wondering if there's a better way, to
replicate the functionality we have with IPv4. Does anyone have any
experience with this?

Regards,

GTG