>Number:         15340
>Category:       bin
>Synopsis:       ssh X11 forwarding is broken
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jan 23 01:59:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     
>Release:        NetBSD 1.5ZA (2002-01-23), NetBSD 1.5.3_ALPHA (2001-10-01)
>Organization:
Matthias Scheler                                  http://scheler.de/~matthias/
>Environment:
System: NetBSD lyssa.zhadum.de 1.5ZA NetBSD 1.5ZA (LYSSA) #0: Tue Jan 22 13:33:11 CET 2002 tron@lyssa.zhadum.de:/src/sys/compile/LYSSA i386
Architecture: i386
Machine: i386

System: NetBSD colwyn.zhadum.de 1.5.3_ALPHA NetBSD 1.5.3_ALPHA (COLWYN) #0: Thu Oct 11 21:58:18 CEST 2001     tron@colwyn.zhadum.de:/src/sys/compile/COLWYN i386
>Description:
The X11 forwarding in NetBSD's SSH works only between two directly connected
hosts. It doesn't work if you try to use a scenario like this:

A:	Host where X11 server runs
	|
	|	SSH with X11 Forwarding
	|
	V
B:	Internet Gateway
	|
	|	SSH with X11 Forwarding
	|
	V
C:	Host behind Internet Gateway

It is not a problem with the SSH configuration on B and C, X11 forwarding
is enabled there. The failure can even be reproduced if you connect from
a NetBSD box to itself two times nested. The same setup works without any
problem on a Solaris 9 box using the included SSH client.

>How-To-Repeat:
ssh host.do.main
ssh host.do.main
xdpyinfo

>Fix:
None provided.
>Release-Note:
>Audit-Trail:
>Unformatted: