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    Link-mtu and tun-mtu warning logged every hour

    Scheduled Pinned Locked Moved OpenVPN
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    • G
      gjaltemba
      last edited by

      My vpn connection is working but I get the following log messages every hour. How to fix?

      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'

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      • P
        phil.davis
        last edited by

        What sort of OpenVPN is it? Is this a client from pfSense up to an internet-VPN service, or a server on pfSense providing road-warrior access, or site-to-site between 2 pfSense, or?

        Do you have anything in the Advanced box of your OpenVPN settings?

        The other end is looking for (hoping for?) a larger maximum transmission unit (MTU) on the link. First it is best to understand why, because your "local" settings there seem more usual to me.

        Once you understand why the higher numbers are needed/preferred you could put in the Advanced box:

        link-mtu 1574;tun-mtu 1532;
        

        to force your end to match the remote.

        As the Greek philosopher Isosceles used to say, "There are 3 sides to every triangle."
        If I helped you, then help someone else - buy someone a gift from the INF catalog http://secure.inf.org/gifts/usd/

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        • G
          gjaltemba
          last edited by

          It is a client from pfSense up to an internet-VPN service.

          Advanced box:
          remote-random
          auth-user-pass
          persist-key
          persist-tun
          tls-client
          comp-lzo
          verb 1

          I have added link-mtu 1574;tun-mtu 1532; and restarted but I see the following in the log:

          openvpn[4644]: /usr/local/sbin/ovpn-linkup ovpnc2 1500 1542 10.12.0.22 10.12.0.21 init

          Thank you for your help

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