keep vpn alive

01. Connect to the VPN (so OSX generates the racoon configuration file)

02. Copy the generated configuration file to /etc/racoon:
    $ sudo cp /var/run/racoon/1.1.1.1.conf /etc/racoon

03. Edit the racoon configuration file with your favorite editor (vim):
    $ sudo vim /etc/racoon/racoon.conf

04. At the bottom of the file comment out the line:
   # include "/var/run/racoon/*.conf" ;

05. ... and instead include the copied file (which we will edit):
   include "/etc/racoon/1.1.1.1.conf" ;

06. Edit the generated configuration file with your favorite editor (vim):
    $ sudo vim /etc/racoon/1.1.1.1.conf

07. Disable dead peer detection:
    dpd_delay 0;

08. Change proposal check to claim from obey:
     proposal_check claim;

09. Change the proposed lifetime in each proposal (24 hours instead of 3600 seconds):
     lifetime time 24 hours;

10. Disconnect and reconnect (this time racoon will use your custom configuration)