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Hi, It took me a while to figure it out, but it seems that if no mssfix option is specified in the config file, the daemon will set it such that all SYN packets passing throught the tunnel are clamped to an MSS of 1369. If I specify mssfix 1464 on both sides, MSS is set correctly to 1382 which is 1464 less 42(crypt) + 20(tunneled IP) + 20(tunneled TCP). This behavior is not described anywhere. Is it a hard-coded default, or is there something else on the system that openvpn uses to determine the default value? On an unrelated note - can someone elaborate on exactly how large is the openvpn overhead? In the calculation above I come up with 42, but then this very same connection ends up sending udp packets with 1461 bytes of payload, which yields an overhead of 39 bytes instead (1461 - 40 - 1382). ______________________ OpenVPN mailing lists https://lists.sourceforge.net/lists/listinfo/openvpn-users |