Re: ppp mru/mtu and ip masquerading

Alan Cox (alan@lxorguk.ukuu.org.uk)
Sun, 28 Feb 1999 17:43:01 +0000 (GMT)


> David Miller asked me for some tcpdumps when I first reported it on
> linux-kernel over a year ago, which I sent, but he was unable to find the
> source of the problem. Toggling ip_no_pmtu_disc has no effect. Sort of
> embarrassing that Linux networking has held this bug for so long.

The Linux networking traces I've seen with MTU discovery all show it working
correctly and faults at remote sites. I have yet to see a single case where
the problem is the Linux end with 2.0.x

With 2.2.x it is entirely possible given the changes to the masquerading
code that a bug has crept in. But I've yet to see a trace for that and it
would be suprising

(If you think about it masquerading doesnt kick in on a download problem
error case. The errored tcp frame bounces off the start of the low MTU
PPP link before it is masqueraded)

Alan

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/