READY_ST
SELECTING_FWD_SERVER_ST
SELECTING_REV_SERVER_ST
REMOVING_FWD_ADDRS_ST
REMOVING_FWD_RRS_ST
PROCESS_REMOVE_FAILED_ST
PROCESS_REMOVE_OK_ST
REMOVING_REV_PTRS_ST
<<DNS IO Callback>>
<<DNS IO Callback>>
<<DNS IO Callback>>
NO_MORE_SERVERS_EVT
END_EVT
UPDATE_OK_EVT
UPDATE_FAILED_EVT
SERVER_SELECTED_EVT
UPDATE_OK_EVT
IO_COMPLETED_EVT
SERVER_SELECTED_EVT
No reverse change requested
END_EVT
Reverse change requested
UPDATE_FAILED_EVT
SERVER_IO_ERROR_EVT
NO_MORE_SERVERS_EVT
UPDATE_OK_EVT
UPDATE_FAILED_EVT
SERVER_IO_ERROR_EVT
Only reverse change requested
START_EVT
Forward change requested
SERVER_IO_ERROR_EVT
IO_COMPLETED_EVT
IO_COMPLETED_EVT