In order to create some special routes for debugging I used the following command on my linux server:
sudo route add -net 10.78.0.0 netmask 255.255.0.0 gw 10.101.1.1
which works, and sets up the routes I need. But when I run the same command on my Mac I get:
route: bad address: netmask
I'm guessing that the version of route that is included in OS X requires a different format but I'm at a loss to figure it out.