On Tue, Mar 09, 2021 at 04:48:43PM +0100, Gert Doering wrote: > No. The code in question is not OS dependent (forward.c, mss.c, no > #ifdef _WIN32 anywhere close to "mss").
Some background: Actually, OpenVPN acts here as a firewall with inspection and mangling, as far as I understand, modifying packets as they flow. This is the equivalent of Linux iptables --clamp-mss-to-pmtu, except this autodetects from the interface, and OpenVPN probably substracts some more headers (its headers) from the total. Normally, the MSS is set during the initial TCP connection opening (the client sets one, the server sets one). Only by changing on-the-fly the TCP MSS can OpenVPN make that the client side, respectively the server side, respects the maximum possible MTU. Obviously this has no impact on UDP traffic.
signature.asc
Description: PGP signature
_______________________________________________ Openvpn-users mailing list Openvpn-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-users
