About half of our MBPs running Sonoma have started rebooting when they connect to our VPN with Viscosity 1.11.5. Not all of our Sonoma MBPs do this, and I haven’t heard anything from our Sequoia or Ventura users about their MBPs rebooting, just some of the Sonoma users. In every case (so far), rolling back to Viscosity 1.11.4 seems to fix it for those affected.
Our standard config is a split-tunnel, TAP-based UDP setup. Aside from a few route / route-ipv6 config updates over the past few years, the config has been fairly stable over the past few years.
Any guesses at what might be causing this? I’m inclined to believe this might be a me thing, but I figured I’d ask here even though I see no other mention of reboots with 1.11.5 in this forum.
Viscosity does not operate at a level where it itself could cause system reboots or kernel panics (as the days of Viscosity using kernel extensions are long gone). It’s generally Endpoint Security Software reacting to network changes that is the cause of such issues.
Such software includes things like Antivirus software, firewall software, device management software, DNS proxies, certain networking tools and drivers, and some other VPN clients. Some endpoint security software (typically installed on enterprise machines) can be quite aggressive and block or inject itself into system processes, which can cause issues.
Version 1.11.5 restored Viscosity’s Virtual Ethernet support for macOS versions prior to macOS 15. If I had to speculate, some endpoint security software is not liking this (it’s probably assuming it’s a hardware network interface rather than a virtual one) and causing a crash or kernel panic. From Viscosity’s end you can try changing the “TAP Driver” setting under Settings->Advanced to “macOS Fake Ethernet” as a workaround (which restores the 1.11.4 behaviour). Although the proper solution is to try removing any potentially conflicting endpoint security software and see if the issue persists.
Your suggestion that it might be the endpoint security software makes sense. All of our laptops have that, and they all run the same version. Maybe how it handles the TAP driver change tickles some bug in macOS 14 that’s not in 13 or 15. It seems reasonable to try digging into it more. I’ll try that the next time I find someone complaining about this problem, or when I can find someone willing to be a guinea pig for me.
Thank you for the suggestion, James.
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