Internet issues on Monterey

The problem hasn't gotten worse for me in 12.3. However, I continue to need to disable the DNS proxy for Cisco's AnyConnect VPN client, which I use for work. I have to disable it every time I restart.

Here is an update - Developers at Apple are getting there slowly - Each subsequent release is getting slightly better in how it handles items such as DNS, USBC ports and the USBC -> Wired Ethernet adapters, etc.

The latest update seems to have straightened out a few of the items but still several annoyances causing me to have to stay tethered to Wi-Fi as this seems stable. For a company of their size, there should have been substantially more real world testing in their Labs to shake problems like this out. I am a professional trying to use these tools daily and expect higher quality from a company this size.

I have requested to provide debugging captures so we can give their developers what is needed to solve these conditions/problems but I get little to no feedback. There are clearly some driver/OS related issues in how they are handling and processing Thunderbolt/USBC ports and managing the protocol stacks and connectivity. I have had scenarios by just unplugging an iPhone from a USBC-Lightning cable, kicks macOS and it somehow resolves items that were stuck.

Just happened again. I tried the following suggestions given earlier:

1) check the number of UDP sockets

netstat -an | grep -e tcp -e udp | wc -l

returned 167 - very small number

2) flush cache and kill mDNSResponder

sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder

Again - no luck.

3) Disabled IPv6 earlier today

networksetup -setv6off Wi-FI 

It didn't help at all.

4) Added earlier new network location "Home" (system Preferences > Network > Location).

When the problem happen I tried to switch between Automatic and Home.

Again - doesn't help.

The only thing that helps is restart. :(

If this can be helpful - I discovered an issue with how Internet connectivity was linked resulting in big speed issues.

MBP M1Max and I use a 600Mb connection and initially I was only getting 1/4 of this speed and also thought something was wrong with the machine, etc. Today my machine is full speed and working fine. Here is what I found:

The Internet Service I use was from Comcast and it arrived on high speed Cable Modem Docsis 3.1 and Gigabit Ethernet and found that it was VERY important to ensure high quality RG6 cabling was used, only 1 splitter of the proper frequency, and the Cable Modem MUST be connected to the first link off this splitter.

Prior to doing these suggestions, I was barely getting 1/4 of the speed and both wired/wireless on the Mac were terrible. After these changes the Mac is running full performance at nearly 600Mbps all the time.

Not sure if this is your situation, but I initially thought the same thing and found out the performance was working

I am still having this problem on 12.6. And I don't use Cisco VPN.

After a few hours the internet stops. In fact what stops is the DNS service, because opened streams (e.g. zoom) continue working. But no URL can be resolved.

Only restart is fixing the problem...

I'm curious to know if the issue you are describing is the same issue my org is dealing with. Some users are reporting that certain applications cannot connect to the internet. It usually effects Zoom and Outlook but only on the application side. The web apps for those same apps will work in-browser. Our security and MDM tools are also effected as the agents/clients on these machines cannot talk (connect) to our managing instances. When running an 'nslookup' to the affected tools, they resolve without issue. But if you run a netcat, the connection is unsuccessful.

We have engineers scrubbing this forum trying to figure out if this could be related to this thread and find a root cause or fix. But it sounds like the issue this thread describes is losing all network traffic once all tcp ports are exhausted.

I just updated last night but there is no issue. BTW,Did you have try setting IPv6 as below?

Simon, did the new Mac come with Monterey already installed or did you have to update to Monterey?

Is it just me or did this issue come back in Monterey version 12.3? I have had to do 2 reboots since installing Monterey yesterday, same reason: DNS no longer works but pinging IP's still works.

Ronasara, thanks but as indicated earlier, this is not affecting everyone using Monterey, so we have to get more specific about differences between devices/configurations being affected and those that aren't.

P. Phillips, thanks for the link. I'll check out those settings when time permits. However, given this article was published on April 12, 2021, and nothing has changed on my network, and Big Sur ran with no DNS issues during this 6 to 7-month time period, the only change I'm able to identify so far is upgrading to macOS Monterey.

You make a very good point. That would most likely help .The problem, as I see it, is who can compile this information about which models are affected or not. More importantly, I think, would turn out to be how the Macs are loaded with certain apps or whatever. The trick wold be to determine why only certain computer's are being affected. Only Apple could undertake such a project and at this time I see nothing to indicate that this kind of data is being collected. It seems clear to me that these varied issues started when Safari version 15 was released. It is now looking like those issues continue with Safari 15.1 which is part of Monterey.

"The trick [is] to determine why only certain computers are being affected."

Bingo!

I wish this were isolated to Safari. Unfortunately, the problem occurs in other browsers too such as Chrome and Edge. It even impacts my Windows 11 virtual machine running in Parallels which depends on macOS for its network connection. But thanks for contributing to our brainstorming session.

It's not any cleaning/optimising/speed up, antivirus or VPN apps in my case - I have 3 macs with the same software and only 1 out of the 3 had this problem.

Mac 1 - iMac in the home

Mac 2 - iMac at work

Mac 3 - MB Air which goes between work and home and everywhere

Mac 1 and 3 frequently use the work Cisco VPN, Mac 2 rarely uses it because it's plugged into work ethernet. Otherwise they all have the same software, all use mainly Safaria and Firefox but have Chrome installed.

Only Mac 1 had a problem. It's not the home network because Mac 3 had not problem with it. It's not VPN because Mac 3 also uses VPN when I need to access work things.

All 3 machines are working fine for nearly a week now. In addition there are 2 other Macs in the house which have had no problem with the upgrade.