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VPN fails to create security tunnel

I am able to connect to both a VPN concentrator and a PIX firewall from three different machines, but the client fails to establish a secure tunnel. I get the message that the virtual adapter failed to enable. It used to work on these machines just fine, and I've not made any changes.


Re: VPN fails to create security tunnel

In a Windows 2000 or Windows XP environment, if the public network matches the private network (for example, a public IP address of, with a subnet mask of, and an identical private IP address) and the public network's route metric is 1, then traffic might not be tunneled to the private network (CSCdz88896). The same problem can occur if you are using a virtual adapter and the public metric is smaller than the virtual adapter metric.

In Windows 2000 and Windows XP, you can increase the metric of the public network by doing the following steps:

Step 1 Select Start > Settings > Control Panel > Network and Dial-up Connections.

Step 2 Select the public interface and click properties for the public interface.

Step 3 Select Internet Protocol (TCP/IP) and get the properties for the Internet Protocol (TCP/IP).

Step 4 Click Advanced, and set the interface metric to 2 or greater.

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