Set –tun-mtu 1500 (currently it is 1532)?



  • I am running a openvpn client connection to my service provider and it is working but I see the following messages in the log repeated hourly. It was suggested that I add tun-mtu 1532 in the Advanced setting to avoid the hourly warning.

    openvpn[56484]: WARNING: 'link-mtu' is used inconsistently, local='link-mtu 1542', remote='link-mtu 1574'
    openvpn[56484]: WARNING: 'tun-mtu' is used inconsistently, local='tun-mtu 1500', remote='tun-mtu 1532'

    With tun-mtu 1532. the hourly warnings are no longer in the log but I see the following at startup. Again the connection seems to be working but what does the message mean?

    openvpn[19435]: WARNING: normally if you use –mssfix and/or --fragment, you should also set --tun-mtu 1500 (currently it is 1532)