Hi, The subject pretty much says it. It's extremely wasteful to be allocating a /64 per subscriber PPP/PPPoE session.
An alternative model is lay a "virtual" /64 over the top of the 100s or 1000s of PPP/PPPoE sessions, and have the subscriber's PPP IID used to autoconf the LL and global addresses. However that's vulnerable to the /64 issues, and because IPv6 over PPP defaults to allowing disabling DAD, could also suffer from duplicate addresses. There is a caveat to allow DAD to be re-enabled, but with cheap residential CPE, that couldn't be relied on. Also it'd be worth making DHCPv6 support announcing a default router/route to these end nodes, so that the upstream BRAS doesn't have to issue periodic RAs. In either the /64 per P2P link or the single "shared" model, with 100s (or more typically 1000s) of subscribers attached, the router will have to spend a reasonable amount of resources on sending RAs down the individual PPP/PPPoE sessions. Regards, Mark. -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
