Disable ForwardX11Timeout without ForwardX11Trusted in OpenSSH Client? By default, recent versions of OpenSSH automatically set `ForwardX11Timeout` to 20 minutes if you set `ForwardX11Trusted` to no. This means that 20 minutes after you start your ssh connection, you can't open any more X clients, because the authentication token has expired. Especially bad if you try to use this with long-lived connections and `ControlMaster`. I've tried disabling by setting to 0 (does not work, causes instant expiration) and by setting to a really long value (do _not_ do this, it will crash your X server. Limit is somewhere between 3 and 4 weeks). How can I completely disable the timeout?

There was a patch 2018-04 and discussion 2018-06 but my search of mailing list archive by subject lines alone suggests it was not yet accepted as of 2019-04.

Duplicating some related info I posted at < just now -

> The maximum timeout is uint_max of milliseconds minus some slack, just over 24 days. OpenSSH_7.4p1 will accept `ssh -o ForwardX11Timeout=2147423s -X ...` which is the best answer I can make now. ForwardX11Timeout above this may crash the XServer in some version combinations.
>
> On MacOS with XQuartz, I have seen `Warning: untrusted X11 forwarding setup failed: xauth key data not generated` and upon digging further, `/opt/X11/bin/xauth: timeout in locking authority file /var/folders/..../xauthfile` .