Using an *external* DHCPv6 server for prefix-delegation in conjunction with PPPoE

[Frank Bulk]

Interesting.  With PVI's I had no issue on the 7206VXR or 7609-S running
12.2(33)SRE2.  I have you tried the "ipv6 dhcp relay source xxxx" option, so
that the source is specified?

BTW, I would recommend running ISC dhcp v4.2 or later.  There's IPv6-related
items fixed/working in v4.2.

Frank

-----Original Message-----
From: Per Carlson [mailto:pelle at hemmop.com] 
Sent: Tuesday, January 11, 2011 1:12 AM
To: frnkblk at iname.com
Cc: ipv6-ops at lists.cluenet.de; ipv6-techsig at mailman.internetnz.net.nz
Subject: Re: Using an *external* DHCPv6 server for prefix-delegation in
conjunction with PPPoE

Hi Frank.

> I'm trying to get our lab bench Cisco 7206VXR (running 12.2(33)SRE2) to
> cooperate with me in regards to using an external DHCPv6 server (ISC v4.2)
> to delegate IPv6 prefixes to CPE.
>
> Any ideas?  Is anyone else doing this?!?

I've got similar results in a somewhat different setup:

interface GigabitEthernet0/2.601
 encapsulation dot1Q 601
 ipv6 enable
 ipv6 dhcp relay destination FD00:8C0:199::199

With this config the relay (7200/NPE-G2 running SRD/SRE) also sends
empty link addresses towards the DHCPv6 server (ISC 4.1 in my case).

The only way I managed to get DHCP-PD working was adding an IPv6
address on the interface + running SLAAC on the CPE.

Reading the RFC (http://tools.ietf.org/html/rfc3315#section-20.1.1)
this behaviour is expected. The Interface-Id option is populated, but
AFAIK ISC can't use that when selecting the scope.

-- 
Pelle

RFC1925, truth 11:
 Every old idea will be proposed again with a different name and
 a different presentation, regardless of whether it works.