[pwnU]

oka so i start my server and i check if its online :http://www.typefish.co.uk/samp-conn/ and it says yes, so i copy the ip adress and put it in my sa multiplayer as a favorite and then i got back and click 0.3c again and all of a sudden it goes back offline, now why is this?

[Mike Garber]

That could be a firewall that detects unexpected traffic and blocks it.

[Pangea]

If you home-host it, you should connect to:

localhost:777

Or what port you use.
If you host it with a hoster, you should use the IP given.

Server shutdowns can also be caused by script faults. But since you didn't even connect it's probably your firewall. Try to add the server.exe into the "allowed" list, or shut your firewall down, for the time you want to open it. ( I recommend you to add the server.exe in the allowed list )