OpenVPN and Path MTU discovery

[skp]

Hi,

Does Path MTU discovery work with OpenVPN? In its default config, does it do anything to disable Path MTU Discovery?
I have an openvpn server that serves multiple clients. It supports TCP only. One of the clients has a path with lower MTU and fails to get traffic from the server. The machine running the openvpn server does get the ICMP from the downstream router asking to fragment (Destination Unreachable, Fragmentation needed), but does not seem to act on it. I still see large frames going out and being dropped on the downstream router.

I set mtu-disc=maybe and that seems to have no affect. I tried mtu-disc=no and that works because the downstream router then does the fragmentation.

tcp_mtu_probing has been set to off on the host running the server.

Any other tcp server running on the host seems to respond correctly to the ICMP. I cannot use "mssfix" because I am using TCP and also because I dont want to affect other clients which have no problem with the MTU.

Is there anything else needed to get OpenVPN to work with Path MTU Discovery?

-sk