[CentOS] Ssh with OS X Tiger (Darwin) and CentOS 4.2

Jim Perrin jperrin at gmail.com
Sun Nov 20 03:50:20 UTC 2005

On 11/19/05, Ryan Lum <cow at launchpc.com> wrote:
> Sorry about being unclear.
> The issue is I cannot create an openssh session from an tiger box to and
> centos box.  The ssh connection actually connects because it will go ahead
> and add the id to known_host, however it takes very a long time.  I have
> tested ssh from a xp/putty box and redhat box that lies out side of my
> network.  Odd thing about the whole thing is it worked yesterday.  I talked
> to the admin and he rest bash on the box, and the OS X box was able to
> connect, but it was still quite slow.  After while the lag was long enough
> to timeout again.  Another admin in the datacenter with a mac said he didn't
> have any problems.  Besides recompiling any other ideas?
> cow at supercow cow $ssh xxx.xxx.com -l xxx
> The authenticity of host 'xxxx.com (xxx.xxx.xxx)' can't be established.
> RSA key fingerprint is xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx.
> Are you sure you want to continue connecting (yes/no)? yes
> Warning: Permanently added 'xxxx.com,xxx.xxx.xxx' (RSA) to the list of known
> hosts.
> Connection closed by xxx.xxx.xxx
> cow at supercow cow $ssh -v
> OpenSSH_3.8.1p1, OpenSSL 0.9.7g 11 Apr 2005

It may be a dns issue. Check to be sure that the machine you're sshing
from has an ip that can be resolved via external dns. If this is not
the case, the USEDNS value of sshd (which defaults to enabled) will
cause slowness, possibly to the point of timing out. You were very
close on the ssh -v, but instead, do ssh -v host_you_want_to_ssh_to.
this will show the connection attempt messages and any errors along
the way. You can do ssh -vv or -vvv for even more verbosity in the

Jim Perrin
System Architect - UIT
Ft Gordon & US Army Signal Center

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