Re: Path MTU discovery and bridged ADSL PPPoE

Toby Corkindale <toby@dryft.net> writes:

However for some reason path MTU discovery has completely broken when using the newer modem. The primary Linux box is fine, but all clients (whether wired, wireless *or even virtual*) fail to work unless I manually set their interfaces to an mtu of 1492.

No one has mentioned it yet, so I will: PMTUD needs ICMP to make it through your firewalls, though I forget which types/code(s). Check the firewalls on all relevant hosts.