virtualbox.org

After successfully installing VBox I am no longer able to communicate with any hosts behind an AT&T VLAN using the host operating system.
The connection appears to authenticate and connect as normal but any attempt to connect to a host on the private VPN network fails even after a host reboot.
I uninstalled VBox and was again able to contact the VPN hosts.
I also have VMWare installed, this works fine and does not impact my ability to connect to VPN hosts.
For the short time I used VirtualBox (during which I created a Windows XP guest and installed the software), I have been impressed.
Although my VBox experimentation has been limited, it appears to me that the virtual guest seems much more responsive than under VMWare, I would really like to continue to use VirtualBox if this problem can be resolved.
Has anyone had similar issues? I can do some more investigation and obtain an IP packet trace and VPN log if anyone is in a position to help.
Thanks in advance.

There have been a few. Put the search below in google and then you can see what others have done to fix this.
AT&T site:forums.virtualbox.org

Many thanks for the reply, indeed there are may people in the same boat as me (not sure if I should feel comforted or not ).
I searched for an open bug report for this problem (which seems to have been introduced in 2.1.2 onwards) so I could monitor it for a fix but without much luck.
Perhaps I/someone should open one?

I will try the advice "For XP, Right Click My Network Places>Properties> Right Click AGN Virtual Network Adapter>Properties>Clear the checkbox on VirtualBox Host Interface Networking Driver>Click OK." in the hope that I can still access VPN resources from both the host and guest OS/es. I will also try re-installing the AT&T client.

Thanks for the help and advice!

Removing the VirtualBox Host Interface Networking Driver from the AT&T adapter did indeed work for me, no reinstall of anything required.
(In fact reinstalling AT&T would also drop this driver out of it's list which is probably why that method also works).
I noticed that there is also a driver for VMWare which is still checked and does not seem to impact VPN operation so there must be something in the VBox driver that gets AT&T confused.

i've encoutered this problem also, but i don't know how to resolved ...

@emperor,
Describe what you have done so far to resolve this.
Have you uninstalled the AT&T VPN client and reinstalled.