2. After making a note of the information, run the following command for each one of the new NIC's that appear as disconnected:
#xe pif-forget uuid=UUID
3. Next, have the system scan for the correct uuids, you will need the uuid of your server (find it with "xe host-list" ):
#xe pif-scan host-uuid=UUID
4. List the NICs again to see what we have found:
5. You should see the correct UUID's of your NICs.
Then, run the following command for each one of the new NIC's to add them back:
#xe pif-plug UUID
At this point your new NICs should appear as connected.