Connection Problem!

Hello, I have a problem…
i cannot join server but i 100% know the server is running my friend are playing on it and iam keep checking gametracker status and its working… I tryed: validating Gmod Files, Reinstalling Garrys mod,Restarting Router and Modem,Reinstalling Steam nothing worked… when i try to join keep getting message Connection failed after 4 retries… iam in contact with admins… iam not banned or anything like that so i dont know… Please help. the server is: Modern-RP

Iam also sorry for my bad English! Thanks