ID:2232295
 
Trying to get my friend into Space Station 13 and he cannot connect to the server I am on. It's a public server with good connection and all that, so it's not the server's end.

On his end he said he let Byond through both Avast firewall and Window's firewall. Is there anything else he can do?
There could be a problem between him and the server, somewhere on the route taken by his ISP. If he can connect to other servers, then it's very unlikely Avast is involved and it's definitely not BYOND.