Packet loss over openvpn bridge


  • Hi all.

    We have a WAN bridge configured between our HQ and datacentre, using pfSense 2.0.2/OpenVPN.  The datacentre end is the server, the HQ the client.  At the HQ side, we have the virtual appliance running without issue on a standalone ESXi 4.1 server.  We want this on our cluster, however when we move the VM or load the appliance in vcenter - while the connection is successful - there is consistent packet loss.  There is no packet loss when pinging the local side of the bridge, but there is packet loss pinging the "local" ip address at the datacentre.

    I'm not sure if this should be in virtualisation forum or OpenVPN, apologies if this is the wrong place!

    thanks in advance for any help.


  • Do you get packet loss outside of the VPN?

    What protocol are you using for the VPN - TCP or UDP? What do the logs from the OpenVPN client and server show?


  • I think i've narrowed it down to teaming.  Creating a second virtual switch on our cluster with a single NIC resolved, adding the second NIC (even in standby mode) caused the fault to occur.  When teaming is configured (even as failover only), the local IP of the pfSense VM responds fine, it's only the remote IP (OpenVPN) where we're seeing packets dropped.  That's why I've kept this in OpenVPN and not VMWare.  If this needs to go to vmware, please let me know.

    We're using TCP for the VPN.  I can't access the machine with the issues again til later.  When that's online, I will get the logs. Thanks


  • OpenVPN on client:

    Feb 18 16:34:31 openvpn[13124]: TCPv4_CLIENT link local (bound): [AF_INET]xx.xx.xx.xx
    Feb 18 16:34:31 openvpn[13124]: TCPv4_CLIENT link remote: [AF_INET]xx.xx.xx.xx:1197
    Feb 18 16:34:31 openvpn[13124]: Peer Connection Initiated with [AF_INET]xx.xx.xx.xx:1197
    Feb 18 16:34:32 openvpn[13124]: Initialization Sequence Completed

    Ping results:
    Packets: Sent = 101, Received = 69, Lost = 32 (31% loss),
    Approximate round trip times in milli-seconds:
    Minimum = 22ms, Maximum = 126ms, Average = 37ms

    OpenVPN on server:
    Feb 18 16:34:28 openvpn[11737]: Inactivity timeout (–ping-restart), restarting
    Feb 18 16:34:28 openvpn[11737]: SIGUSR1[soft,ping-restart] received, process restarting
    Feb 18 16:34:29 openvpn[11737]: NOTE: the current –script-security setting may allow this configuration to call user-defined scripts
    Feb 18 16:34:29 openvpn[11737]: Re-using pre-shared static key
    Feb 18 16:34:29 openvpn[11737]: Preserving previous TUN/TAP instance: ovpns1
    Feb 18 16:34:29 openvpn[11737]: Listening for incoming TCP connection on [AF_INET]xx.xx.xx.xx:1197
    Feb 18 16:34:31 openvpn[11737]: TCP connection established with [AF_INET]xx.xx.xx.xx:1765
    Feb 18 16:34:31 openvpn[11737]: TCPv4_SERVER link local (bound): [AF_INET]xx.xx.xx.xx:1197
    Feb 18 16:34:31 openvpn[11737]: TCPv4_SERVER link remote: [AF_INET]xx.xx.xx.xx:1765
    Feb 18 16:34:31 openvpn[11737]: Peer Connection Initiated with [AF_INET]xx.xx.xx.xx:1765
    Feb 18 16:34:32 openvpn[11737]: Initialization Sequence Completed

    As you can see, these logs show the initial connection but there is nothing after that.