It is possible that the two LoadMasters are able to communicate but the ILB might be misconfigured. Connect to both units on http://LoadMasterAddress:8444. On the active unit, you should see "Active/Standby is active". On the standby, you should see a 503 service unavailable error. If you see these messages, it means the LoadMasters are working correctly and the problem is elsewhere. Confirm that the health check probe on the ILB is configured correctly.