OPENVPN Client : unable to resolve dns name when trying to reconnect



  • Hi !
    I use a 2.0-RELEASE (i386) built on Tue Sep 13 17:00:00 EDT 2011

    I have an OPENVPN client connected to a VPN provider with a "redirect-gateway def1" for routing all my trafic through the VPN, it work very well, but after 7 or 8 days the connection goes done and try to restart with a loop error : unable to solve dns name of my VPN Provider.
    And of course I still want that all my DNS request goes through the VPN
    To try to solve that i did the following config in the System->General Setup

    DNS Servers
    X.X.X.X with use gateway my OpenVPNInterface
    X.X.X.X with use gateway WAN

    All the Two checkbox are unchecked

    But how can i be sure my dns request are always going through the OpenVPNInterface and only use WAN when OpenVPNInterface goes done and try to solve DNS name to restart ? Nslookup don't give you the route used to solve the DNS name. (i use nslookup debug mode with no result)

    Thx  ;)

    papou



  • @papou:

    But how can i be sure my dns request are always going through the OpenVPNInterface and only use WAN when OpenVPNInterface goes done and try to solve DNS name to restart ? Nslookup don't give you the route used to solve the DNS name. (i use nslookup debug mode with no result)

    I think i have answered myself the question by using tcpdump on UDP 53 to listen DNS request

    tcpdump -n -i myopenvpninterface 'udp port 53'

    I also did it in // on my WAN interface
    tcpdump -n -i mywaninterface 'udp port 53'

    And i saw the following things with this DNS configuration :

    X.X.X.X with use gateway my OpenVPNInterface
    X.X.X.X with use gateway WAN

    I have the two DNS request going in // on the two interface  >:(

    now with this DNS configuration :
    X.X.X.X with use gateway my OpenVPNInterface
    X.X.X.X with use gateway None

    I have the DNS request going only through OpenVPNInterface :)
    and if i restart the OpenVPNInterface the DNS request going through WAN and then through OpenVPNInterface when it become up  ;D

    So it seems to work as i want with this configuration  :D

    I now will see if my VPN connexion resolve the DNS when it will restart in few days….



  • Hi,

    thanks for your feedback. Please post your results (in a few days).


Log in to reply