Resetting Cisco VPN on a Mac?

Question

Sometimes our Macs will get

Error 51: Unable to communicate with the VPN subsystem.
Please make sure that you have at least one network
interface that is currently active and has an IP
address and start this application again.

when starting Cisco VPN.

Rebooting doesn't help. Reinstalling requires reconfiguring the settings.

What's the best way to reset Cisco VPN when we get this error?

Answer 1

Alternative command:

sudo SystemStarter restart CiscoVPN

Answer 2

From a terminal window:

sudo /System/Library/StartupItems/CiscoVPN/CiscoVPN restart