[rbak-nsp] SE-100, PPPoE and PMTU issues?

[Geert Jan de Groot]

Hi folks,

While this list is intended for the ISP side of things, I apologise
for asking a question on the "customer" side of things.

Our ISP at $dayjob recently started a pilot to make IPv6 available
to us. We are the first (and, so far, only) customer so far.

Connectivity is provided via PPPoE using an SE100. As the core side
seems to be natively connected and we're connected through PPPoE,
the box is supposed to send PMTU packets when full-size ethernet
packets are sent from the Internet to us.
To make a long story short, it does not send ICMP PMTU messages
(well, I see them once or twice in a full hour of sending various-size
packets, but not every time a large packet is sent).

When I send 2K ping packets, I only see the 2nd packet on the PPPoE port,
the first packet is completely missing and the source doesn't see
any ICMP traffic back either. This does work correctly on earlier hops.

Secondly, the box doesn't show up on traceroute, so either it doesn't
send ICMP TTL exceeded messages, or something is filtering them,
but we do see one hop up and one hop down, just not the SE-100.

Being a pilot project, I have worked with the ISP but this has not
resolved the issue - took a while to convince him there is a problem
(in his tests, the CPE box did MSS clamping, which our FreeBSD
border box does not do and which is not an acceptable solution for us),
and he now is stuck on this as well.

Ericsson support has been amazingly useless. For starters, manuals
are not accessible (I don't own a box, I just want to read about it),
the Dutch Ericsson sales office doesn't know Ericsson sells these products,
and the Sweden headoffice referred me to an office in Duesseldorf,
which seems to have a broken PBX (I get "falsche wahl" when I dial
to get the operator), which is a but surprizing for a "phone company".
At this point I believe all the money in the world would not buy
me a box; not sure if I want one either, given the experience above;
given the prices of this kit, I'd kind of expected different support.

I'm wondering if this is a configuration issue or whether something
else is happening. I have a few questions:
1. Is it true that (what our ISP claims), the box only provides IPv6
   over PPPoE, not natively? We'd rather have native IPv6 and be done
   with the whole PPP mess.
2. Does anyone have IPv6 PPPoE working? Experiences, good or bad?
3. Has anyone seen issues (or: not seen issues) with scenarios
   requiring PMTU to work? Does the box send PMTU packets as it
   is supposed to?
4. Is not generating responses in traceroute a standard feature or
   is this a configuration issue?
5. Any other wisdom, good or bad?

If you want to experiment yourself, traceroute to 2a01:670:520:142::2, 
but since it's a test it may not be up all the time.

Again, my apologies for this intrusion on this list.

Geert Jan