macOS Monterey 12.0.1 and intermittent network connectivity

Exactly the same problem here. I've ruled out google wifi (colleagues with the same problem that don't use google wifi) and I've identified CiscoAnyconnect as the culprit. It's doing something weird with mDNS.

To see the problem manifest, run the following command in a terminal "netstat -an | wc -l" - this lists out (more or less) the number of open network connections your computer has. I've noticed that day on day this number grows to a number around 300,000 at which point the network dies - exhausted ports would be my guess. The only thing I can do at that point is reboot.

Now, why do I think it's Anyconnect? I uninstalled Anyconnect (and rebooted) - the problem went away - lines the command I provided above sits around 800. Installed Anyconnect - problem came back, uninstalled (and rebooted) and the problem went away.

Now.. the big question is - is it a problem for Cisco or Apple to fix?

I saw the same, connections jumping up rapidly until I uninstalled Anyconnect. I googled this and also found this post: https://community.cisco.com/t5/vpn/macos-monterey-and-wifi/td-p/4508944 which found they only needed to remove  CiscoAnyconnect Socket Filters in Network preferences, not uninstall completely. They are re-added if you restart though. :(

Hopefully Cisco or Apple fixes this soon.

I just finished with apple support and they fixed my Monterey 12.1 google mesh issue. Network, advanced, TCP/IP change configure IPv4 to Using DHCP (was previously set to DHCP manual address). Problem solved on both Monterey computers.

I was having the same issue on Monterey 12.1 and the current 12.2.1 but I don't have Cisco AnyConnect installed. However, I did have Cisco AMP for Endpoints security application installed. I uninstalled AMP yesterday and the disconnects have not recurred. Something with these later versions of Monterey and Cisco products is wonky. I have had AMP installed for over a year with no issues until Monterey.

Update your Monterey Mac to 12.3 as this might make a difference since there will be plentiful bug fixes from 12.0.1. Also, confirm that you are current with any firmware updates for your router that may make it play nicer with Monterey.

My struggles with this same issue--including Cisco AnyConnect--have resolved after my upgrade to 12.3. It looks like it might have been an Apple issue and they fixed it.

The company I work at has same issue for anyone with Anyconnect installed - macOS 11 or 12, through 12 seems more impacted. Seems related to an Anyconnect update in the Fall to coincide with Monterey release. Our IT guys have been trying for months to find the smoking gun. Only oddity found so far is that if you look at netstat output on impacted machines and look at IPv4 UDP connections, there is a crazy number of connections that just grows and grows with destination IP address of the vpn concentrator on port 53 (DNS)

A colleague suggests that Apple are coming out with a fix assuming this is indeed our problem:

"An update regarding the issue some of you are experiencing with Umbrella becoming unresponsive: it looks like it's an Apple MacOS 12 bug which is causing it (anyconnect is just a symptom). The release notes for MacOS 12.2 seem to indicate Apple are fixing it :

'Resolves an issue where Network Extensions may intermittently lose connectivity after long periods of use.'"

Is there a moderator that can comment with more info?

I just moved into a new apartment with Google Fiber and I thought private relay was the issue as well... turns out the solution was editing my network location?

More here: https://discussions.apple.com/thread/253335091?answerId=253335091021#253335091021

After adjusting my network location and creating a "New Location" all of a sudden all my network issues resolved and I can use Private Relay and my VPN without issue.

No explanation for why this fixes it, I'm just suggesting you try it...

Update Monterey to 12.2.1 and retest your network connectivity for non-reboot improvements. When 12.3 arrives, apply it and test again. Apple may have munged something in earlier releases of Monterey that is causing collateral impact, or that some configuration in your network devices is incompatible with Monterey.

I am not using a Google Nest Mesh router…

I have the same issue. Monterey 12.1, Google Nest Wifi mesh, Cisco 4.10.01075. I have likewise come to the conclusion it has something to do with Cisco and particularly the socket filters. I have many machines running fine, and it's only the one with Monterey and Cisco AnyConnect with the issue, which started right after upgrade to Monterey in Nov 2021. I don't know how this slipped through the bug testing at Cisco and/or Apple, but it's a rough problem, killing video calls, etc. Urgent!

Is this statement accurate " macOS Monterey 12.0.1 and intermittent network connectivity " ?

Reason asking, as of this writing the current version of Monterey is 12.2.1

It brings several bug and security fixes and may or may not be related to the computer issue being experienced.

Do suggest performing a Time Machine Backup before attempting to update.

Try what I posted above https://discussions.apple.com/thread/253459149?answerId=256702674022#256702674022

Removing the Cisco client worked for me.

Same here, it's been (finally) stable since 12.2.1. (no reinstall of Anyconnect)