ssh tunneling and "channel 2: open failed: administratively prohibited: open failed"

[Rick Sewill]

On Tue, 2007-01-23 at 18:39 +0000, Jonathan Underwood wrote:
> On 23/01/07, Rick Sewill <rsewill at cableone.net> wrote:
> > > ssh  -R 8888:C:22 username at B cat -
> > >
> >
> > My first guess was to suggest using
> > ssh -N -L 8888:C:22 username at B
> >
> > I believe -L 8888 forwards port 8888 on Machine A through ssh to machine
> > C, port 22.
> 
> Ah, yes, sorry, that's exactly what I did do (I thinko'd -R instead of
> -L in my description). I've just repeated these test using -L, and get
> the error message in the subject.
> 
> 
> >
> > I assume /etc/ssh/sshd_config, on Machine B, has not been changed from
> > the default of allowing TCP Forwarding (AllowTCPForwarding)
> >
> 
> Unfortunately I can't access /etc/ssh/sshd_config on that machine (B)
> as I don't have route access. uname -ar on that machine gives SunOS
> xxx.xx.xx.xxx.  5.10 Generic_118833-17 sun4u sparc SUNW,Sun-Fire-V440.
> ssh -V gives Sun_SSH_1.1, SSH protocols 1.5/2.0, OpenSSL. I don't know
> any way of checking if TCP forwarding is allowed on that machine.
> 

When you ssh from machine A to machine B, 
can you ssh from machine B to machine C?

It may not provide much information, but my next instinct would be to
turn on verbose mode, "man ssh" 
ssh -v -v -v -p 8888 localhost
The reason I say it may not provide much information is because, for
security reasons, sshd on machine B (or sshd on machine C if you are
actually getting to machine C) will wish to divulge as little
information as possible why the connection is being administratively
prohibited.

-- 
Rick Sewill            tel:+1-218-287-1075 mailto:rsewill at cableone.net
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