You have probably misconfigured the IP or port the server is supposed to run at. If you are behind NAT, make sure you didn't entered your external IP to the server's config file.
OK, could you post your server's config file here? BTW, if you want to run a server, you should at least know the difference between external(public) IP and the internal one. If you have a router, you'll need to open a port on it to allow other people to connect to your server. Have you read the guide?
The dedi server comes with a "setup.cfg" file. This is where everything from admin password to allowed cars is read from and you must edit the file accordingly the get the server going.