Quake 3 Arena LAN between OS X and Windows

We're trying to have a LAN party, I'm on a El Capitan (10.11.3) Mac and my fellows are on PCs with Windows.

Now, when they host, there's nothing I see and I'm not able to connect with \connect ip-address. When I host they can even see me in the servers list, but still unable to connect.

Anyone managed to accomplish this? Should I edit my Network preferences in any particular way?

P.S.: there's no Firewall or anything on my Mac.