Re: little bit off topic CLAT-Daemon for 464xlat for "Linux" (not android)

[Bjørn Mork <bjorn mork no>]

Tore Anderson <tore fud no> writes:
> * Thomas Schäfer
>
> > echo 1 > /proc/sys/net/ipv6/conf/eth0/proxy_ndp
> > ip -6 neigh add proxy 2001:6f8:120c::c1a7 dev eth0
>
> Aha, so that's how it's done. Yep, this'll work, although it isn't
> strictly RFC compliant., which demands that the IPv6 address you pick
> must be «defended with Duplicate Address Detection».
>
> > Back to the original intention. Is it useful to integrate this in the
> > NetworkManager on "normal" Linux-Desktops?
>
> I would find 464XLAT an useful addition, yes. Although I'm not really
> sure if doing it with TAYGA would be optimal, as it doesn't appear to
> have seen any developement in the last three years. I would have
> preferred to see an in-kernel implementation of SIIT, I think.

FWIW I've had a tayga NAT64 test setup running at home all those three
years and I'm inclined to believe it hasn't seen any development because
it's already complete :-)

I know that is a strange thing to say about any software, but the fact
is that tayga works really well.  And it also scales surprisingly
well. I cannot see any reason to replace tayga with an in-kernel
implementation.  You'll either do fine with tayga, or you'll buy some
hardware accelerated NAT64 solution.  There just isn't any need for
in-kernel software based NAT64.

> - If we can rely on all 3GPP modems that are operating in fake Ethernet
> mode to do blind forwarding of all IPv6 traffic to the MAC address of
> the fake Ethernet interface without doing NS for them first (my HP
> hs2350 a.k.a. Ericsson F5321gw behaves like that), you don't have to
> muck about with ND proxy at all.

I don't think you can rely on this.  There are modem firmwares requring
NS between modem and host, even if it is meaningless.  Thomas knows :-)

But I don't think the CLAT feature should be tied to 3GPP in any case,
even if that's where it is most likely to be used.  It could be made
more generic, depending on:
 a) no IPv4 default route, and
 b) IPv6 default route points to an interface with a /64 prefix and
    autoconf true, and
 c) NAT64 detected

If all these are true, then it makes sense to enable CLAT.  The outgoing
interface type doesn't matter.

> While I believe that 464XLAT is most useful on 3GPP mobile links (that's
> what it was designed for, after wll), it would be cool to have NM
> support it on Ethernet as well.

Agreed!



Bjørn