When winbindd starts, it spawns an smbd(IPC$ chanel) for RPC->pingDC. Then this smbd hangs in the running state and doesn't terminate. Is this expected behavior, or should the smbd only run for a limited time? Winbind itself does not terminate the connection on port 445, judging by source3/winbindd/winbindd_cm.c. Samba version 4.19.9