[AusNOG] IPv6 Prefix Delegations from Aussie BB - Private or Routeable?

[David Rawling]

Hi all

Seeking some advice from people who do this kind of thing all the time.

I have an IPv6 prefix (::/48) delegated from the ISP (Aussie BB) and
for about the last two years that PD has been routed and accessible
from the raw unfiltered Internet. Shows up on the portal etc. It's been
configured mostly static, as I didn't have time to try to figure out
PD.

A few days ago that subnet stopped working completely. It's still
delegated, and the router can even hand out the delegated addresses,
but nothing routes. I've now had multiple responses from the support
team claiming that

> IPv6 /48 subnets in IA-PD address's are only usable for LAN. The IPv6
/64
> subnet is the only one that can be used outside of a LAN scope.

The subnet being delegated seems to be a regulation IPv6 subnet - it's
part of the 2403:5800::/28 delegated to Aussie Broadband by APNIC.

Am I missing something obvious here? Shouldn't a PD normally be routed
(why would I bother getting a PD from the ISP if it's not routable
space - I'd just use something from fd00::)? Are ABB really enforcing
NAT/NPT on a protocol designed not to need it any more? It's still
delegated to my nameservers for reverse resolution, which I think
wouldn't be needed if it wasn't routable in the first place. And the
corresponding IPv4 routed subnet is fine.

Does anyone else have a PD from Aussie Broadband, obviously on a
business plan of some sort is preferred, where the PD subnets are
routable? Alternatively - am I just being dumb? I could be dumb, it's a
day ending in a Y...

For reference it's a simple architecture where the PD should be usable
on the LAN side of the router, but isn't:

ABB <---> IPv6 DHCP --[ROUTER]-- IPv6 PD <---> [FW]

Dave.
-- 
David Rawling - Principal Consultant
PD Consulting and Security

t: +61 41 213 5513 | e: djr at pdconsec.net

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