Been diddling with Bonjour Browser and Little Snitch.
I called Apple Tech about the network listings and Bonjour activity I was seeing. Gad, mainlanders are intense folks. Not idle "Talking Story" with him.
I asked if Bonjour could be turned off. He said it was really slick and allowed easy establishment of local networks. Since I was directly connected to the modem, my local network included other folks on the cable. Told me to put my router back in and my local network would be just stuff my side of the router.
Did that and there are zero items on my network and Bonjour is not talking to anyone. Suppose my PC would show up if I turned it on but that I understand.
Little Snitch - activity was limited to things I expected (Mail, Camino). She does ask about allowing things to use Ports but I understand because they are in response to things I've initiated.
Another thread which might be of interest:
https://forums.macrumors.com/threads/779592/
This I don't understand -
With the router back in, there was very little modem activity. Nothing odd for about 45 minutes.
Then Time Machine did a scheduled backup. The modem lit up and Little Snitch reported constant activity on mDNSResponder, alternating between ns.oceanic.com and dns2.oceanic.net (Oceanic [Time Warner] is my ISP).
Can't see why my ISP needs know anything after a Time Machine backup.
Got to thinking that the modem activity which got me all excited about this after the SL upgrade never happened until some time had passed with the computer active. Might be coincidence but it had started right after Time Machine did its thing this time.
Did a Restart of the computer. Normal modem startup activity and then all quiet. Little modem, Activity Monitor or Little Snitch action. KUHL!
After a few minutes, I forced a Time Machine Back Up Now. My modem, Activity Monitor and Little Snitch (mDNSResponder Oceanic) began to party.
Turned Time Machine off, put the computer to sleep.
This morning I had no unexpected activity for about 3 hours. Finished what I need to do and did a test - forced a Time Machine Back Up Now. My modem, Activity Monitor and Little Snitch (mDNSResponder Oceanic) began to party.
Did a Restart of the computer. Normal modem startup activity and then all quiet. Little modem, Activity Monitor or Little Snitch action. After 10 minutes, I forced a Time Machine Back Up Now. My modem, Activity Monitor and Little Snitch (mDNSResponder Oceanic) began to party.
Did the above 3 times with same result. Bit of a stretch to think it is coincidence.
Curious, eh?