I installed the Cisco VPN Client 5.0.07.0290 on Windows XP SP3, with Comodo Free Firewall, and had some trouble getting everything working.
The first problem was with my old D-Link Router, it was blocking the UDP reply packets when the client attempted to connect. This router has no VPN function to allow UDP VPNs to pass through the inbound firewall. I could have turned on Virtual Server for IPsec, but that would have only solved the problem for one machine. I went into Advanced mode on the Cisco client, and changed the transport from UDP to TCP. This allowed the stateful firewall in the D-link to recognize the connection and correctly route the reply packets.
This brought me up to the username and password screen, unfortunately as soon as the password was accepted, the computer would halt with a blue screen of death (BSOD) error 0x000000BE, An attempt was made to write read only memory. A Google search led me here http://forums.techguy.org/networking/73 ... reens.html. The problem was a conflict between the Zonealarm firewall built into the Cisco client, and my Comodo firewall.
I uninstalled the Cisco Client, and followed the instructions from this article http://www.cisco.com/en/US/products/sw/ ... 2dbe.shtml. I then reinstalled the Cisco Client without the firewall using the command: msiexec.exe /i vpnclient_setup.msi DONTINSTALLFIREWALL=1
After reinstalling, I again changed the VPN transport from UDP to TCP, clicked the connect button, and logged in. Joy at last.
The first problem was with my old D-Link Router, it was blocking the UDP reply packets when the client attempted to connect. This router has no VPN function to allow UDP VPNs to pass through the inbound firewall. I could have turned on Virtual Server for IPsec, but that would have only solved the problem for one machine. I went into Advanced mode on the Cisco client, and changed the transport from UDP to TCP. This allowed the stateful firewall in the D-link to recognize the connection and correctly route the reply packets.
This brought me up to the username and password screen, unfortunately as soon as the password was accepted, the computer would halt with a blue screen of death (BSOD) error 0x000000BE, An attempt was made to write read only memory. A Google search led me here http://forums.techguy.org/networking/73 ... reens.html. The problem was a conflict between the Zonealarm firewall built into the Cisco client, and my Comodo firewall.
I uninstalled the Cisco Client, and followed the instructions from this article http://www.cisco.com/en/US/products/sw/ ... 2dbe.shtml. I then reinstalled the Cisco Client without the firewall using the command: msiexec.exe /i vpnclient_setup.msi DONTINSTALLFIREWALL=1
After reinstalling, I again changed the VPN transport from UDP to TCP, clicked the connect button, and logged in. Joy at last.
