Hi,
The port needs to be open on the agent host. Check if a firewall is running on the agent host:
# service iptables status
If the firewall is running, you either need to open port 8145 on it or turn it off. Run the following command to turn off the port:
# service iptables stop
To test if the connectivity has been restored, go to the Inventory page in the SnapCenter GUI and select 'Refresh Resources'
Refer: https://kb.netapp.com/support/s/article/ka11A0000001XOAQA2/SnapCenter-Oracle-Plug-in-installation-fails-with-Plug-in-incompatible (requires login)