Internet issues on Monterey

Ok everyone. I've devoted a massive amount of time and resources on this issue and wanted to share our findings.

1) Apple's Cross-Platform Engineering team is aware of this issue, and has been struggling on nailing it down as it manifests slightly differently for each customer.

2) We have validated this issue exists on Big Sur, Monterey, and Ventura

3) Our findings indicate that the main cause of the "locked" ports is network drive mappings utilizing SMB

a) We have validated this on a fresh out of the box Mac, no security agents, socket filters, or MDM installed. ONLY Active Directory joined and mapped network drives. We have uploaded all data to Apple.

b) Mapping network drives instantly will start creating these locked ports

4) Creating a nsmb.conf file, and using that to change SMB mount behavior from hard mounts to soft mounts eliminates any locked port creation. We are in process of validating this on a build with the full load of security agents and socket filters. First 18 hours of testing is showing zero locked ports. I've included the script we are deploying via JAMF to create this config file at the bottom of this reply.

Hopefully this info helps others who are also struggling. To be clear, the changes I outlined are not a true fix, as the underlying root cause is in Apple's hands at this point. However, it does eliminate the symptoms and prevent the network disconnect issues from occurring.

Script to create the nsmb.conf file

#!/bin/zsh

cat << 'EOF' > /etc/nsmb.conf

[default]

soft=yes

EOF

chown root:wheel /etc/nsmb.conf

chmod 744 /etc/nsmb.conf

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.

Have you installed or run any "cleaning", "optimizing", "speed-up", anti-virus or VPN apps on your Mac?

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

Monterey 12.2 was release two days ago. Update to it and see if the problem persists.

On my M1 Max MBP:

The long dead spot was right after logging in.

Same software on my 2011 MBP running 10.13.6

Not a router issue - not an application issue...

Anyone from Apple look at these forums?

FWIW, I've been testing Monterey for about 5 months on three different Macs. I've had no connection issues. All three are basically on 24/7. It does seem like it's something local to your machine.

I have also installed Monterey and so far everything is working just fine. Maybe a little bit faster, or so it seems.

Thanks this worked for me

No issues on Mac Mini M1 or BMA M1 both upgraded from Big Sur 11.6.1 to Monterey 12.0.1. Actually somewhat faster too.

An update from me, after about 3 days of restarting, it magically fixed itself. It is now working beautifully on all machines.

How many days have your Macs running Monterey been trouble-free? For me it's been happening once every 24 to 48 hours, so I'd still be on the lookout if it's only been one or two days...

My wife and I have two recent iMacs and both are running Monterey with no problems.

I have the same issue, problem lies on dns inability to resolve a hostname, and so far the only fix is to reboot the laptop. macos version 12.0.1, Macbook pro 13-inch 2020.