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U-M Virtual Private Network (VPN)

Known Issues & Bugs

Firewalls

Some problems have been discovered when using the Cisco VPN Client in conjunction with Firewall software. The easiest way to fix this is to disable the firewall. However, that is not an advised long term solution. Also, here are a few specific examples:

The ZoneAlarm firewall can be incompatible with the Cisco VPN Client

When running Zone Labs Security software with a Cisco VPN Client, you may receive the VPN error message, "System Error: Unable to retrieve connection status." To avoid this, add the client computer's loopback address to the Trusted Zone, and give access permission and server permission to the Cisco VPN Client.

When you install Cisco VPN Client, then install a 4.x version of Zone Labs Security software, Zone Labs Security software upgrades a dll that is also used by the Cisco VPN Client. If you either uninstall Zone Labs Security software 4.x or install an earlier version, you must also uninstall the Cisco VPN Client, otherwise the shared dll will not be downgraded to a compatible version.

The Outpost firewall can prevent connections, even when disabled

Many U-M users have the Outpost firewall on their laptops since it is the "preferred" firewall of the U-M Blue Disk. Even though you may try turning this firewall off, you may still have problems connecting with the Cisco VPN Client. Older versions of the Outpost package have to not exist on the laptop, because it is presumably altering the Windows networking components. See Get Outpost working with Cisco VPN for more information.

Ports needed to allow VPN access

If you have a firewall running on your computer, you should make sure to configure it to allow certain protocols so VPN traffic will pass through successfully.

Linksys v4 Model Cards

Many users have reported the inability to establish a wireless connection with Linksys v4 wireless cards. Older models of Linksys cards (e.g. v3) do not have this problem. CAEN has been in contact with Linksys, and they acknowledge that there is a bug with their card interacting with VPN networks. Linksys is working on the problem. We will update this page with any new information.

If you do experience this problem, make sure you have the newest version of the Cisco VPN Client and make sure to install the most up-to-date drivers for your Linksys v4 card. Although, due to the bug, there is still no guarantee that this will work. You can download the new wireless card driver, contained in wpc11v4_061303.zip from ftp://ftp.linksys.com/beta/.

Other Issues

For further examples of some known issues with the Cisco VPN Client, please see the Cisco Release Notes for VPN Client.