Server Question

Is there any way to fix the problem I'm having. You see it seems like other people can find Esf servers without the Ip but I cannot is there any way to fix this cause I want to find the -Ox- Clan Servers but when I type the ip it searches for 255.255.255.255 instead of the right Ip any explanation or fixin for either of my problems.

You are behind a firewall or a router that keeps your server hidden, contact your isp