VyOS 1.3.3 - Clamping MSS, how?

The documentation doesnt really seem to be the right thing. How would I clamp TCP MSS for my tun0 adapter on VyOS 1.3.3?

Try the command like this:

set firewall options interface tun0 adjust-mss 1300


try these 2 articles
Connect to the FLET’S provider with PPPoE with Proxmox + VyOS 1.2.8 LTS (zenn.dev)

PPPoE Sub-interfaces : VyOS Support Portal

This is an old solution. No need to setup tcp-mss as a policy.

Policy route needs if you want to set mss for inbound packets.
So, it is not old; it just sets TCP-MSS for different directions.
You can dump traffic in one and another option and check in/out packets.


Great, Thanks! Such as wireguard or gre tunnel interface. Which one should we use?

use this blog as reference it will help