Re: Path MTU discovery and bridged ADSL PPPoE

On 26/09/13 11:19, Toby Corkindale wrote:

Well, putting this iptables rule at the head of my FORWARD chain solves the problem: iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

I still have absolutely no idea why this worked fine on one router, and fails on another though!

That only works for TCP, you will probably still have problems with large UDP transfers.