On multi nic systems the task client may use an undesired NIC to attempt to communicate to the Task Server. None
working as designed
To prevent agent communcation on a specific NIC go to this registry on the client:
Add a Multi String Value named ExcludeMACFromUniqueKeys
Then populate the value of the MAC address of the NIC that is on the network you do not want the task client to communicate on. Note: remove any spaces or dashes in the MAC.
Alternativly you can add a Multi Sting Value named ExcludeDeviceIDFromUniqueKeys then add the Device ID
Restart the Symantec Mangement Agent and the agent should no longer attempt to communicate on that NIC.
If this works then you will need to ether manually populate this registry on client machines or create a script to do it.