[Fwbuilder-discussion] Clamp MSS to MTU

[Nicole H. <nic...@gm...>]

Hi,

I have to add this rule in fwbuilder:
iptables -t mangle -A POSTROUTING -p tcp -m tcp --tcp-flags SYN,RST SYN 
-j TCPMSS --clamp-mss-to-pmtu

How can I add this?

Activation Clamp MSS to MTU in firewall settings does not work for us.

We are running strongswan vpn on our servers, and strongswan adds for 
each vpn tunnel
a new rule with "iptables -I FORWARD 1", so every new rule pushes the 
ClampMSS rule down,
but this rule has to be on top.

Thanks!
Nicole