Looking at an OpenVPN server configuration - I'm pretty sure something is not right with the settings. Performance is not that great, it tends to be slower than expected when doing massive transfers, though it generally works okay.
CentOS 6, openvpn-2.4.7
dev-type tun
proto udp
tun-mtu 9000
fragment 0
mssfix 0
However, the MTU on the physical interface eth0 is 1500.
The other end of the tunnel is on a different continent, the connection runs over the public Internet. The other end has similar settings.
Running tcpdump, I see the VPN packets sent out of this server via eth0 are up to 1445 (or 1473) bytes in size. However, tcpdump always reports offset 0. I assume that means the 1194/udp packets sent out of this server are not fragmented.
Is it correct to assume that in this case the tun-mtu is ignored?
Whether or not it is ignored, will it impact performance?
(The oconf BB tag does not work for me, sorry.)
