Your company has a main office and is adding a branch office. The main office and the new branch each have an ISA Server 2006 computer. You want to connect the main office and the branch office networks by using a site-to-site VPN. You create a site-to-site VPN connection that connects the office networks by using the L2TP over IPSec VPN protocol. Computer certificates are installed on the ISA Server computer at each office. When you create the remote site network on each ISA Server computer, you configure it to use certificates and a preshared key. At each office, the preshared key is configured as the office name on the ISA Server computer at that office.
From the ISA Server computer at the main office, you repeatedly run the ping command to a host on the branch office network. The site-to-site VPN fails. You open the Routing and Remote Access console and manually dial the demand-dial interface. You receive the following error message: The last connection attempt failed because: The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer.
You need to enable the site-to-site VPN connection by using the most secure IPSec authentication method possible.
What should you do?
A.
Restart the ISA Server computer at both offices.
B.
Re-enter the preshared keys on the ISA Server computer at both offices. Change the preshared keys so that they include mixed-case letters, numbers, and symbols.
C.
Remove the preshared key from the remote site network configuration on the ISA Server computer at both offices
D.
Delete the remote site network on the ISA Server computer at both offices, and re-create the remote site networks with the original parameters.