READY_ST
SELECTING_FWD_SERVER_ST
SELECTING_REV_SERVER_ST
ADDING_FWD_ADDRS_ST
REPLACING_FWD_ADDRS_ST
PROCESS_ADD_FAILED_ST
PROCESS_ADD_OK_ST
<<DNS IO Callback>>
<<DNS IO Callback>>
<<DNS IO Callback>>
UPDATE_FAILED_EVT
SERVER_IO_ERROR_EVT
FQDN_IN_USE_EVT
SERVER_IO_ERROR_EVT
FQDN_NOT_IN_USE_EVT
UPDATE_OK_EVT
No reverse change requested
START_EVT
END_EVT
UPDATE_OK_EVT
UPDATE_FAILED_EVT
Reverse change requested
END_EVT
NO_MORE_SERVERS_EVT
SERVER_SELECTED_EVT
IO_COMPLETED_EVT
REPLACING_REV_PTRS_ST
Forward change requested
Only reverse change requested
SERVER_IO_ERROR_EVT
SERVER_SELECTED_ST
UPDATE_OK_EVT
IO_COMPLETED_EVT
IO_COMPLETED_EVT