How to permanently add a route in OS X?

I have a Mac Pro and the problem is that it is not connecting to systems in other VLANs. This can be temporarily archived by

sudo route -n add -net <IP>/mask <Gateway>

However it vanishes in the next laptop restart. How can I add the route permanently?

2 Answers

I myself didn't manage to make it work with the solution that pabo provided. I ended up running it in the crontab:

env EDITOR=nano crontab -e

add the script line:

@reboot sh /path/to/your/script.sh

make sure that if you need sudo rights, you would need to disable password for sudo use for your script. More info here:

Additionally, if you are using some build in commands in mac, like for example route you need to specify full path of the binary file. Here is example of script.sh file:

sudo /sbin/route add 192.168.64.0/16 192.168.100.1

Found an article which suggests adding something like this

ifconfig en2 inet 11.22.33.5 netmask 255.255.255.252
route -n add 11.22.33.64/26 111.222.333.6

to /etc/rc.common. Apparently the preceding ifconfig line is necessary, though I don't know why.