I'm trying to route just specific traffic (a specific domain) on my Mac over my company VPN. This seems to be the most recommended way to do it,
Create the file /etc/ppp/ip-up with following content:
#!/bin/sh /sbin/route add SUBNET $5 replacing SUBNET with subnet, you want to route through VPN (for ex. 192.168.0.0/16)
execute as root:
chmod 0755 /etc/ppp/ip-up This file will be executed each time you connect to VPN.
...but I don't understand how to determine the SUBNET value. Do I need to create a subnet? Is the subnet name for the VPN in network preferences somewhere? I really don't have a good idea of what a subnet even is, so I'm not following how to implement the solution above.