ssh and X

[Paul Jakma]

Hi,

I'm having weird problems with ssh and X forwarding. I have some
stuff in my login scripts to set various xkb preferences (in case I'm
not logged in via GNOME), however this now produces:

XKB extension not present on localhost:10.0

Which is confusing. My Xserver supports XKB, how come it doesnt with
clients talking to it over a forwarded ssh tunnel?

Or sometimes, I login to a remote machine and the first x command
works, but then sometime later xlib will complain that connections
are refused, eg:

Xlib: connection to "localhost:14.0" refused by server

Which I cant understand - how did it work before that, did ssh stop
forwarding the connection after a while?

All very strange. Anyone have any insights?

regards,

[Paul Jakma]

Which is confusing. My Xserver supports XKB, how come it doesnt with clients
talking to it over a forwarded ssh tunnel?

Eg:

Xdpyinfo over the ssh X forward:

number of extensions: 3
BIG-REQUESTS
LBX
XC-MISC

Xorg Xserver supports a lot more extensions... what is up exactly? Is
my ssh or the remote sshd somehow filtering X / acting as an X proxy?

regards,

[Paul Jakma]

The answer appears to be:

Use '-Y' "trusted X" forwarding, not -X. (at least with FC3's 3.9p1
ssh client).

Thanks to pron on #linux.

Bonus points to anyone who can explain what this new "-Y" forwarding
is, and wtf they've done to ye olde X forwarding (-X) in 3.9p1
clients as shipped by Fedora.

regards,
--
Paul Jakma ***@clubi.ie ***@jakma.org Key ID: 64A2FF6A
Fortune:
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[Paul Jakma]

Post by Paul Jakma
Bonus points to anyone who can explain what this new "-Y"
forwarding is, and wtf they've done to ye olde X forwarding (-X) in
3.9p1 clients as shipped by Fedora.

And the answer is in the man page obviously. Seems regular X
forwarding is filtered by ssh now, you need to set:

ForwardX11Trusted yes

in ~/.ssh/config to get the unfiltered X forwarding. Which is
required, as the filtering breaks lots of X apps for me at least.

Post by Paul Jakma
regards,

[P***@draigBrady.com]

Use '-Y' "trusted X" forwarding, not -X. (at least with FC3's 3.9p1 ssh
client).
Thanks to pron on #linux.
Bonus points to anyone who can explain what this new "-Y" forwarding is,
and wtf they've done to ye olde X forwarding (-X) in 3.9p1 clients as
shipped by Fedora.
regards,

https://www.redhat.com/archives/fedora-devel-list/2005-January/thread.html#00190
--
Pádraig Brady - http://www.pixelbeat.org
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