Thursday, January 08, 2009

How to flush Cisco's VPN on a Mac

Cisco's VPN client usually works very well, however sometimes a weird issues pops up. If you get the issue of a 51 error (no subsystem with Internet communications) and in fact have an established connection with an IP address, this workaround will help. Rebooting does not seem to help in these cases.

1. Assuming you have installed the VPN client in the default location, open a shell.
2. You must be su to make this work so type the following:
"sudo /System/Library/StartupItems/CiscoVPN/CiscoVPN restart"
3. This is case sensitive. If it works, you should see the results as shown below.

Hopefully, Cisco will figure out why the Mac OS X communications subsystem does not correctly represent its state to the VPN Client.


  1. When connecting thru the vpn connection, you don't need to worry about portforwarding. You can connect to any port at the vpn server, hence VNC should work without any hazzle. At least that's the case for me after setting up a similar connection. I connect with VNC, thru VNC to my home server. You should also consider rdp, since you're using windows

  2. You might not worry about port-forwarding but you do need to worry about paying the bills

    (VPN Server)


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