System management Server

The node was connected to a system management server before, the machine started to issue a warning that is not connected to the SMS anymore, when we try to connect it back to the existing SMS, we get an error, stating failed to configure device, Unable to connect to the remote server bacause the target machine is actively refusing it 10.17.8.5:80, that IP address on the error message is not correct, it does not exist in the entire domain, Host file with correct IP address is configured on both sides. is there is config file that I can update to clear that wrong IP address?