Hi, I am struggling with MTU Problems with a lot of clients, which usually results in unusable slow connections.
So I was thinking on how to solve the problem so that almost any client can connect to my VPN regardless if their ISP has a reduced MTU. After a lot of reading about this MTU topic and possible solutions with OpenVPN, I was more confused than enlightened, because the possible solutions vary and the documentation regarding MTU options is not unambiguous. Therefore I would like to ask you for some advice regarding MTU problems and solutions and furthermore some comments on my solutions or if I made some mistakes (e.g. calculating the MTUs). Following on I will only give the OpenVPN options of relevance. The VPN Server is reachable through IPv4+IPv6 and has also IPv4+IPv6 inside the tunnel, so it is completely Dual-Stack. proto udp6 server *some IPv4 net* server-ipv6 *some IPv6 net* Basically I came up with two solutions: 1. using a combination of tun-mtu 1500 fragment 1300 mssfix to let the the tunnel appear with a normal MTU even when the ISP can not handle it and let OpenVPN fragment the packages so that they will fit through the Internet connection. Or 2. make actually the tunnel smaller and let the operating-system fragment the packets: tun-mtu 1300 mssfix 1360 In a test with several different clients I found out, that the second solution is about 10-20% faster than the first one but has a 30% longer ping. I favourite the second solution for now, but I am not sure if my mssfix value makes any sense. Furthermore some clients report some speed/ping problems with both solutions. I appreciate any help and insight :) Best regards, Kor ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Openvpn-users mailing list Openvpn-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-users
