[Server not showing up in list?]

I have 2 hosting servers one here and one with G-Portal, and with G-portal the admins tell me that this is a problem what forest need to solve, the know the problem but not a sollution atm.

 

greets Seta

[Why can't find the server in the list]

Hello Guys,

 

I Setup a server and i cannot see him in the list, 

 

Some other friends can see him and join him, 

 

and sometimes i can see him and join but i think 90% i cannot see him

 

Do i need something to change on my Computer 

 

ill try all sort of things in my router and firewall but nothing helps me out

 

Regards Seta