Client Override fails on Win10 OpenVPN GUI

  • My pfsense is running 2.3.3-RELEASE-p1, with OpenVPN configured for multiple remote users.  In general everything is working fine for remote Linux, Mac & Windows clients.

    I have created a Client Overrides for one user in order to restrict access to a specific LAN IP.  The config seems to work fine for OSX Tunnelblick, but Windows fails to connect for this new user.

    I have searched the forums & googled but cannot seem to find the correct answer.

    Tue May 23 12:33:58 2017 WARNING: Since you are using –dev tun with a point-to-point topology, the second argument to --ifconfig must be an IP address.  You are using something ( that looks more like a netmask. (silence this warning with --ifconfig-nowarn)
    Tue May 23 12:33:58 2017 There is a problem in your selection of --ifconfig endpoints [local=, remote=].  The local and remote VPN endpoints must exist within the same subnet.  This is a limitation of –dev tun when used with the TAP-WIN32 driver.  Try 'openvpn --show-valid-subnets' option for more info.
    Tue May 23 12:33:58 2017 Exiting due to fatal error

    Server Tunnel =
    Common Subnet for all clients

    In Client Override, I added the following:
    Common Name = Client Name
    Tunnel Network =
    IPV4 Local Network =  (the IP I want to limit this client access to)

    Advanced = empty

    I have tried various ifconfig & route options to no avail.

  • Rebel Alliance Developer Netgate

    Is your server set for net30 or subnet topology?

    If you are using net30, try clearing out the tunnel network and setting it in advanced settings of the override:


    It's also possible your windows client is very, very out-of-date. Uninstall it and the tap driver and install the latest version again.

  • Server is set for Subnet topology.

    I haven't tried Net30.  Will this require other changes such as FW Rules, etc ?

    The Windows client is the 2.4.0 installer provided within the Client Export package, so hopefully not out-of-date.

  • Rebel Alliance Developer Netgate

    If you are on subnet topology, then the error message from windows is wrong. So either something isn't correct in the windows client, or somehow the wrong settings are being used by the client.

    I would definitely uninstall and then reinstall the client on windows. And if that doesn't change anything, post the full client log here along with the client config (redact any private info, but keep the directives visible). The server config would be helpful to see as well.

  • Ok I uninstalled & re-installed the 2.4.0 OpenVPN GUI Client using the download from PfSense export package.  Still same issue.

    Attached are:

    • pfsense OpenVPN server config including Client Specifics
    • VPN Client Config
    • VPN Client Log

    In all cases the Public IP has been replaced with 999.999.999.999 plus Key & Cert specifics removed


  • Rebel Alliance Developer Netgate

    If you are on subnet topology, your client-specific override entry tunnel network MUST have a matching mask for the server tunnel network. Change that to See if that helps.

  • @jimp:


    Thanks to all.  Even though I'm using Subnet mode, I tried clearing the Tunnel Network box, and added this to Advanced instead,  and then restarted OpenVPN Server.  Now my Windoze client connects and restricts the user to the specific IP in the CSC.

    All that remains now is to add FW rule to restrict him to HTTPS only for the GUI he needs access to !!


  • LAYER 8 Netgate

    Pass rule on the OpenVPN tab for his source address port any server's dest address port 443
    Reject rule for his source address dest any

    You will also need to pass DNS, etc if that needs to work over the tunnel.

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