Make sure the port is 9091 and username is compuware with password vantage. You spelled it incorrectly in your post topic. More info here:
If it still doesn't connect try a the following command on the AMD and then try connecting again.
service rtmgate restart
I would also check to see if HTTP or HTTPS is enabled and which port the AMD is configured to use. You can check this using rtminst.
Most likely causes I've encountered are firewall issues.