It turns out there’s a shelf life for Apple’s MacBooks when it comes to how long they can be left turned on before users lose their network connection. Per a report from Photon, MacBook users need to keep track of how long their MacBooks have been left on, or else after exactly 49 days, 17 hours, 2 minutes, and yes, precisely 47 seconds (cue the Mission Impossible theme music here), a system-imposed limit will stop network connectivity.
While it’s somewhat common for workstation PCs to be left on 24/7 in various scenarios, it is a bit rarer for users to do the same with their laptops. However, for those who use a MacBook, they should perhaps be aware that a legacy setting is counting down, and this “Time Bomb” bug will eventually reach an overflow point. Photon has a detailed crash course for those not knowledgeable about TCP, timestamps, MSL, and 32-bit unsigned integer wraparound, but the short end of it all is that this bug has been around for a while now, and Apple is not the first to “feature” it. Windows 95/98 notoriously also suffered from it, and similar instances have been found with Unix systems with the Y2K38, yes, 2038 Y2K style, GPS OSes, and well, Pac-Man if players somehow made it past level 255.
This bug was actually found by chance when a fleet of machines was intentionally left running 24/7 to perform various testing and monitoring tasks. At exactly 49.7 days following their last round of reboots, something completely unexpected happened; they stopped renewing their TCP connections, but oddly enough, could still be pinged. However, rather hilariously, a tried and true solution once again saved the day, just reboot it already (cue “Have you tried turning it off and on again”).
It’s nice to know that Apple users are left with the same path as Windows and Android users when it comes to such a catastrophic issue. Photon has since reproduced this on multiple machines and has a very detailed report on what is occurring and is working on a fix beyond reboots, but until then, users are advised to keep track of how long their devices have been left on and to do a restart before the bomb goes off.