First time OVH user - proper firewall setup to allow the server to show up?

[Cheezus]

Basically the title. I've got a new dedicated box with OVH and this is my first time using them. I'm able to set up the firewall to allow players to join the server via the connect command in the console, however the server does not show up in the master list and does not respond to A2S requests. Anyone here use OVH and know what the proper firewall setup for GMod is?