How to maintain multiple persistent vpnc connections on ubuntu

Question

Mark Knowles' Blog has a good explanation on how to maintain a persistent vpnc connection. However, this doesn't work well for multiple vpnc connections (Connecting doesn't work for me, everything gets reconnected on a single disconnect, ...). Is there a better way of maintaining multiple vpnc connections?

Answer 1

The following modifications work well for multiple profiles:

1. Add Local Port 0 to your .conf files in /etc/vpnc, if you haven't done so. This will use random local ports, and will allow multiple connections better.

2. For every connection, pick an IP and port on the vpn network which you want to connect to (and maintain a connection to). For every connection, write a script in /usr/local/bin that checks the connection is still possible and if not launches vpnc, e.g. EnsureVPNXXX.sh with

   #!/bin/bash
   if ! nc -z -w 2 targetip targetport
   then /usr/sbin/vpnc-connect connectionprofile.conf
   fi
   

3. Change the reconnect script /etc/vpnc/reconnect-script to use all of those EnsureXXX.sh scripts (do them one after another, so no & at the end)

   #!/bin/bash
   sleep 30
   /usr/local/bin/EnsureVPN1XXX.sh
   /usr/local/bin/EnsureVPN2XXX.sh
   ...
   

4. The /etc/init.d/vpnc script is almost the same, except you don't need to source /etc/default/vpnc any longer

Don't forget that scripts need to be executable. As long as you call them from root, these scripts work very well in any automated cron-jobs, e.g. before you call scp or rdesktop on any box in the vpn network, just do a quite EnsureVPNxxx.sh. You can always drop back out of root with a su -u yourusername command. And use root's crontab, obviously.