Mac OS Big Sur - Norton Firewall Blocks everything

Originally posted in Norton Forum:
"Hi Gayathri,
Thank you for your message. Indeed I had to turn off the Norton Firewall ("Verbindungsblocker" in German = connection blocker) as well as the Button below ("Schutz vor Sicherheitslücken" = Protection against security breaches). Now it works fine, however Norton does show up with its annoying messages that my computer is not protected."

My reply to Norton Forum fyi:
"POSSIBLE WORKAROUNDS to Try?

I am a Parallels on Mac user and have experienced similar blocking problems on earlier versions of Mac OS/ Norton 360 Mac/ Parallels when using Parallels Hardware/ Network/ Shared Network setting, which manifested itself as excessive CPU use on the Mac side (and the fan ramped up to cool the Mac). It took Symantec some time to sort out Norton 360 on the Mac for these earlier Mac OS/ Parallels versions.

I am am now running Mac OS Big Sur/ Parallels Version 16.1.1 (49141)/ Norton 360 8.6 Mac/ Norton 360 Win10

Back to the the same old problem of Support saying to reinstall to fix (it doesn't) ... cpu loading up (prl_naptd) and the fans sounding like a jet engine, etc.

Experiments I have tried/ am trying ...

(1) Uninstall Norton for Mac (include using the Norton clean up tool to entirely wipe clean) and just relying on good old Mac firewall on the Mac and Norton 360 on the Parallels/ Windows 10 side ... using Parallels Hardware/ Network/ Shared Network setting, or ...

(2) Retain Norton 360 on the Mac side and Norton 360 on the Parallels/ Win 10 side and use the Parallels Hardware/ Network/ Default Adapter (Bridged Network) setting ... a work around I successfully used on the earlier combinations of Mac OS/ Norton 360 Mac/ Parallels/ Win 10.

In both cases ... no more Mac CPU loading by the "prl_naptd" process and the Mac laptop fan going into "takeoff mode".

I prefer option (2) above, as it retains independent Norton 360 protection on both the Mac and Win10 sides of the fence.

Hopefully this feedback can help Symantec home in on a fix for Mac ... given Big Sur required a big architecture change for App suppliers, including Symantec ... assumes a product engineer reads it I guess!"

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Not sure if the PARALLEL team has any insights.

 

HI Parallels Team ... not important enough for you to pursue?

 

Update - I have been focussing on settings in Norton 360 having followed/ contributing dialog on a similar Norton Forum.
I have made the following settings in Norton 360 Mac which (so far) have allowed me to use Parallels Shared Networking without anymore heavy CPU loading evident by "prl_naptd" and "prl_disp_service" - currently 0 to 0.1% - the added new N360 settings are:

1) Firewall > Connection Blocking > Settings > Editing (Trusted Network) > Zones > Trust Zone (allowed addresses) > + (or add IP address) - I added
both my Routers full range of local area IP addresses plus the Parallels virtual subnet range of IP addresses (10.211.55.1 to 10.211.55.255)
2) Firewall > Vulnerability Protection > Settings > Exclusions > Add > All IP addresses on network

NOTE - You have to consider security settings for your own situation - the above are my personal settings only.
If you are not sure or get stuck use the online Norton support methods to chat with one of their technicians.