Yep, I concur: this explains a bizarre behavior I’ve noted in my Mac laptops for ages now. I have a tendency to just suspend them without rebooting for ages, especially the work one that doesn’t leave my office as frequently. Periodically, I’d come in to find the system bizarrely frozen just as they describe: TCP stack blocked up, but everything else on it behaving normally. (Well, mostly: some apps would block starting and bounce eternally, but I suspect that’s because they’re trying to make a network call while starting up and it’s blocking.) The only fix was a reboot.

It’s not a disaster, but very annoying. At least now I can just schedule a reboot every 30 days at minimum to keep things running.