The host name specified for the installation or retrieved from the system is incorrect

When implementing the Agent Deployment setup on a newly created Oracle Enterprise Manager 11g. I sometimes ran into the problem that a server just would not accept to setup the Agent Push mechanisch.
The error that would be shown in OEM 11g is :

PROBLEM : The host name specified for the installation or retrieved from the system is incorrect.
WARNING : Check complete. The overall result of this check is: Failed <<<<
RECOMMENDATION : Make sure your host name should meet required criteria.

After checking the host file and DNS settings on this machine i came up empty. Hostname and Fully Qualified Domain Name ( FQDN ) are correct.
The one thing that i did not check but was the problem on which this process fails is “hostname”

When you issue this command the “real” registered hostname is given back. ( only hostname or fqdn )
As this was different then the name i issued during the setup in OEM 11g , the process was unable to match the 2 as equivilent and therefor resulted in an error.

I could backtrack this behaviour in the file which indeed retrieves the hostname by issueing ‘hostname’ to match the given hostname in OEM11g.
This has been reported as a bug 4679997 in 10.2.x version , but as it seems still exists in 11g

2. Hostnames used to set up SSH connectivity via the script must be identical to the hostnames listed in the Agent Deploy application (Bug 4679997)
Using a fully qualified domain name (e.g. “”) in one and a non-qualified hostname (e.g. “host8”) in the other will cause the Agent Deploy application to fail.

Make sure to use the exactly the same hostname in both the SSH connectivity setup script and the Agent Deploy UI.