Poor Man’s Always On VPN

In the need for a simple and easy to use OS X based Always On VPN solution? If so, I may have something for you.

We are using a straight forward L2TP over IPSec VPN connection for connecting into our Pentesting lab. Beside giving me access to many of my most needed tools it also allows me to surf the web without any proxy or firewall limitation. As I encountered several VPN disconnects over my work day I decided to solve it once an forever by automatically reconnecting the VPN after a dropout.

To do so I wrote the following Apple Script based on this Apple Support Communities discussion.

global PING_HOST
global VPN_NAME

set PING_HOST to "vpn.example.com" # A host on the web to ensure the current connection is working at all
set VPN_NAME to "Your VPN" # The name of the VPN connection to dial (works with PPTP, L2TP over IPSec and Cisco IPSec)

on idle

	try
		# as the ping causes an exception if no response is received we only try to connect to the server if it's really reachable and thereby surpress error messages
		do shell script "ping -c 1 -W 500 " & PING_HOST

		tell application "System Events"
			tell current location of network preferences
				set myConnection to the service VPN_NAME
				if myConnection is not null then
					if current configuration of myConnection is not connected then
						connect myConnection
					end if
				end if
			end tell
		end tell

	end try

	return 2 # schedule to run again in two seconds
end idle

Simply save it as an application and check the box “Stay open after run handler”:

As long as the App it is running, your VPN connection will be redialed automatically. This small helper gained a permanent spot in my Dock!

PS: To give the App a nicer appearance you may want to change it’s icon to this free one. Here is a tutorial on how to do that.

Edit: Updated the code to use the “on idle” handler