Disable network device for specified period of time

Recently I converted an old MacBook into a server, running OS X 10.6.8 (the normal, non-server edition). I use it as my VPN server, my bittorrent rsync server, web server, ssh server and so forth.

Sometimes I manually disconnect the LAN cable from my server to speed up my connection for online gaming, afterwards I plug back the LAN cable.

What is a good way to temporary disable the LAN device on my MacBook running OS X 10.6.8? Preferably that it automatically enables again after a specified period of time (some sort of timer). I would prefer a method via SSH.

Selfcontrol

Selfcontrol is an app build for a different purpose, it disables your network connectivity for a certain amount of time to keep you from visiting social websites and keep you more productive. It makes it possible for you to create a white-list or a black-list to allow or block certain ip-adress/sites.

So I login to the server, set Selfcontrol to 1h. Now my internet connection from my server is disabled for 1h and will automatically come back afterwards.