openconnect on macOS

Daniel Lenski dlenski at
Tue Nov 30 10:28:38 PST 2021

On Tue, Nov 30, 2021 at 7:36 AM Frank Winkler <oc at> wrote:
> I've been using oc on Linux and macOS for quite a while now and it
> worked fine so far. Since I upgraded to macOS 12, it seems that oc is
> crashing the entire network stack after running for some time.

Can you clarify what "crashing the entire network stack" means?
Ideally with logs etc.

Are you using the utun driver, as recommended for all modern versions
of MacOS?

> Connections get slower and slower and then new connections cannot be
> created, ending up with socket errors. I didn't find a way to cure the
> system unless I reboot. Is there a known incompatibility to macOS 12?

We haven't had any previous reports of system-wide degradation like
this, as far as I know 🤷🏻‍♂️.

None of the core OpenConnect developers regularly use MacOS, and we
don't have any good way to do automated testing on MacOS, so we rely
on user reports for this.

> And as the last update is one and a half years old, is there any further
> development?

Yes, lots and lots of it, including new protocols, performance and
usability improvements, and more. See and links to build
instructions from there.


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