Registering Linux host using Navisphere Host Agent

On EMC KB site i found few articles which I compiled togather the information togather for my future references

If a Host shows up as unmanaged/unreachable in Navisphere.Or the Host does not register with the fully qualified host name and IP address, then you can follow these steps to fix the issue:

First step you need to Verify if port 6389 is open. Navisphere Host Agent uses the /etc/hostfile on a Linux host to create the HostIDFile.txt file. Navisphere uses the HostIDFile.txt file to register the host. In order for the host to register and show up as being managed the /etc/hostfile should contain the fully qualified host name and the IP address MUST be included in the hostfile.

Hostfile example:
# Do not remove the following line, or various programs# that require network functionality will fail.127.0.0.1 localhost.localdomain localhost10.21.41.61 testvmesx1.test.com.au testvmesx1

If there are multiple entries, comment out all but the entries that you want the host to register to the CLARiiON with. (Once the host registers, the user can then uncomment the entries in the /etc/hostfile.) Once the appropriate changes have been made, cd into the /var/log directory. Locate HostIDFile.txt and delete it. Stop and start the Navisphere Host Agent.
Once the host Agent starts, a new HostIDFile.txt will be created. From Navisphere Manager, right-click the array and click Update Now. Then under the hosts tab, right-click the host, select Properties, and verify that next to Operating System the Agent is reporting the correct operating system.