3 Replies Latest reply: Jan 16, 2009 4:32 PM by mgcAlanB RSS

    DNS Breaks in VMware Guest OS when Host OS Connects with Cisco VPN

    mgcAlanB Novice

       

      Facts:

      • VMware Workstation v6.5.1 build-126130

      • Cisco VPN Client v4.8.02.0010

      • Host system: Win XP SP2

      • Guest system: Win XP SP2

      • Both XP systems: All Windows Updates current/complete

       

       

       

       

       

      Scenario 1:

      • Host OS is connected to VPN

      • Guest OS is then started under VMware Workstation

      • Guest OS cannot connect to any of the VPN servers

      • Moreover, the Guest OS cannot even PING any of the VPN servers

      • NSLOOKUP in Guest OS cannot determine the proper IP address for any of the VPN servers, either

       

       

       

      Scenario 2:

      • Disconnect Host OS from VPN

      • Guest OS is still up and running from Scenario 1

      • Guest OS can now PING any of the VPN servers

      • Now, reconnect Host OS to VPN

      • Guest OS can STILL ping any of the VPN servers

      • Guest OS can also connect to any of the VPN servers

      • Once Guest OS disconnects from VPN server, it - once again - cannot even PING any of the VPN servers ...

      • ... unless I disconnect the Host OS from VPN, again

       

       

       

      Scenario 3:

      • Edit the Guest OS' "hosts" file (C:\windows\system32\drivers\etc\hosts)

      • Connect and disconnect from VPN in Guest OS w/o need to disconnect Host OS from VPN, ever.

       

       

       

       

       

       

      What is it with the Cisco VPN client on the host OS that is adversely affecting the DNS on the guest OS??!!

       

       

       

       

       

        • 1. Re: DNS Breaks in VMware Guest OS when Host OS Connects with Cisco VPN
          Scissor Virtuoso User Moderators

          Please check that you have the latest driver for your Host's network card installed.

           

          Then, can you try a test and temporarily turn off any "task offload" or other "offload" settings under the properties for your Host's network card to see if it makes a difference?

           

          Are you running any 3rd party firewalls on your Host or Guest (BlackICE, Symantec Network Protection, etc)?  What antivirus do you have installed?

          • 2. Re: DNS Breaks in VMware Guest OS when Host OS Connects with Cisco VPN
            guyrleech Virtuoso

             

            This sounds like fairly standard VPN client behaviour which is to stop any incoming traffic when the VPN is up. Where is your DNS server with respect to the guest? If you need network connectivity, it "might* be possible to add another NIC to the host , use that as a manually bridged adapter, and not let the VPN client manage that link although there are no guarantees.

             

             

             

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            • 3. Re: DNS Breaks in VMware Guest OS when Host OS Connects with Cisco VPN
              mgcAlanB Novice

               

              This all used to work just fine and dandy under VMware Workstation_6.0.5

               

               

               

               

               

              Since upgrading to 6.5.1, it's not behaving as it used to.

               

               

               

               

               

              As for firewalls, we now use Symantec Endpoint  Protection. It, too, is new on the system. But, as I outlined, by merely disconnecting temporarily, the guest OS can connect to VPN once it was able to ping it successfully.