Re: [2.1.47] Bug in Path MTU or PPP(?)

Alan Cox (
Fri, 1 Aug 1997 09:46:37 +0100 (BST)

> can get to most sites without problem). I can access them from my system
> normally, and if I bump the MRU up to 1500, then it will work for them,
> too. Here is a sample of a failed tcpdump session under an MRU of 768:

Looks like the system you are dialing into has an MTU discovery problem or
someone firewalled ICMP packets on it. Note btw that the 1500 MRU is notionally
the lowest allowable in PPP, although most kit correctly and usefully allows
and negotiates lower values.