Over at Ian Talks Tech my friend Macca recently posted a fix for the “Error 51 : Unable to communicate with the VPN subsystem” error from a cisco vpn client. I had also encountered the same problem some time ago and it brought my own memories rushing back. I had initially discovered a fix for the error 51 problem over at a different site, Anders.com . Since finding the one line terminal command answer to the issue that my cisco 3000 client had thrown up I thought no more of it. Ian’s post jogged my memory about my own search and I immediately put my copy and paste skills to good use to come up with an apple script that you can run to fix this cisco vpn client error.
All you need to do is open the apple script editor.
Then paste a similar line of code to the commands that Macca and Anders mentioned:
do shell script "ifconfig fw0 down" with administrator privileges do shell script "ifconfig fw0 up" with administrator privileges and password do shell script "/System/Library/StartupItems/CiscoVPN/CiscoVPN restart" with administrator privileges and password
Feel free to run the apple script to test it, just note you will be asked for an administrator password for the script to run.
Once you are happy you should compile and save the script to keep it safe, or “save as” and choose application. Alternatively, you could just download the AppleScript Fix for the “Error 51: Unable to communicate with the VPN subsystem” problem, that I have pre compiled as an application.