It might be best opening a case with the emc connectivity team after collecting complete logs.
As we need to know the specific version of DCNM that is having issues.
The complete logs can be usually be collected by following the article listed below.
The following questions help in understanding the issue you are facing?
- What version of DCNM-SAN are you running?
- At the DCNM-SAN login screen, does the DCNM Server field point to the IP address of the DCNM server, or is it localhost? If it shows localhost, please try changing this to the IP address of the DCNM server. If the IP address of the server is shown in this field, please verify that the correct IP address is displayed.
- Have you tried restarting the DCNM-SAN and Database (Oracle/PostgreSQL) services? Or just rebooted the server itself?
- Is the server a physical or virtual machine?
- Can you also verify that the firewall settings have not been modified? The following knowledgebase article outlines the ports required by Fabric Manager / DCNM and which should be excluded from the firewall:
We also have seen some instances where the Java is the issue and it is advised to uninstall Java completely and re install Java. Once the Java is re install make sure to reboot the server and try connecting the DCNM server.
One additional article
You might check the following article also in case its relevant https://support.emc.com/kb/88386