Re: IPV6 router works, but clients fail

[Roy Marples <roy%marples.name@localhost>]

Miles Nordin wrote:
> > > > > > "rm" == Roy Marples <roy%marples.name@localhost> writes:
>
>     rm> http://mail-index.netbsd.org/regional-london/2006/09/14/0000.html
>
> oh you are fucking kidding me.
>
> well, the problem is still on your end, though.  It's just in your
> modem instead of in your PF rules.
>
> Could you try to get a different modem?  I have a BroadXTent modem
> that grabs its address over PPPoE, then hands the address it grabs to
> the connected host using DHCP with a short lease.  If you had a modem
> like mine which used PPPoA instead, then in PPPoA mode you could get
> the full 1500 mtu, no?  Some googling found this:
>
>  http://www.wenks.ch/fabian/ADSL-PPPoA.html
>
> Another alternative is to use Cisco CPE like 1721+WIC-1ADSL or 857 and
> terminate the IPv6 on the Cisco.
>
> What's the point of this translation to PPPoE that Matthias says his
> modem is doing?  It seems really odd.  I'd think if the modem were
> speaking PPPoA it would certainly handle all the passwords and
> terminate the PPPoA on the modem, after which it would either act as a
> normal router doing its own NAT, or else at the weirdest pass to you
> its local PPPoA IP in that nonstandard proxyarp/fakeDHCP way of which
> my BroadXtent modem is capable.

This is the modem recommended by my ISP so can I get native IPv6 
working. AFAIK it's not possible with my old modem, a DrayTek Vigor 2600 
which oddly enough is listed in your link.

At the time of purchase, no ADSL modem in the UK could handle IPv6 that 
I could see, except for Cisco routers which are well outside of my price 
 range by a few hundred pounds. So going for the Vigor100 for a PPPoA 
PPPoE bridge was a no brainer as then my server could handle PPPoE + IPv6.

> Is it for certain the modem is really converting PPPoA<->PPPoE like
> this, and not just that the DSLAM in the CO works in a variety of
> modes (oA, oE) among which you can choose, and the oE mode is broken
> for v6?  I hope it's the modem that's broken not the DSLAM since you
> can swap the modem out, but I doubt the story because this is the
> first I've heard of a modem doing that.

I'm pretty sure the UK is PPPoA only so it would have to be a bridge.
Maybe there are some settings on the vigor I can tweak, or maybe try and 
adjust the PPPoE MTU to 1500?

> I suppose you'll ignore this and keep using the mss clamping.  but
> FYI, it is really broken.

No, as it really is a hack.
I'll probably end up just enforcing an MTU of 1492 on the network as I 
control all the client side equipment. I just hope that my games 
consoles obey the MTU DHCP setting :)

Thanks

Roy