All NPRs on a site are giving 'Host Lost / Host Restore' alarms, but the TCP/IP network is functioning 100%.
Changes to bin file revisions sometimes include updates to communication
This can be caused by a mis-match in .bin file revisions on all downloadable controllers. Verify all the .bin files in each downloadable controller are from the current I/NET revision at the customer's site.
The mis-match can come from a tech loading a .bin file from his laptop (with a different rev than the customer). It can also occur when I/NET is upgraded, but the controllers aren't.