Subject: Re: Slow SSH connection
To: Chris Bartlett <cb@mythtech.net>
From: Bill Studenmund <wrstuden@netbsd.org>
List: port-mac68k
Date: 07/23/2002 18:23:25
On Mon, 17 Jun 2002, Chris Bartlett wrote:

> >This is normal. OS X's ssh defaults to ssh2, which does take a lot of
> >startup time on slower machines. The startup time is acceptable on 68060s
> >and faster processors, but I usually use ssh1 when connecting to my
> >68040s, VAX, and SPARC (SS2) machines.
>
> MacSSH claims to be an SSH2 only client, and that only has about a 10
> second lag on connect (which is fine by me). I'll still try OS X under
> SSH1 anyway, at least to narrow down what might be causing it.
>
> I did run the SSH with the verbose option, and it hangs on the stage
> "debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY" which would certainly seem
> like it is waiting for the NetBSD machine to do something. I haven't had
> a chance to do a google on that line yet to see what it means exactly (we
> had a heavy rain storm here last night, and every time we do, my home DSL
> starts dropping packets like crazy for 2 days... must be a loose cabinet
> door on a nearby junction box leaking water or something... so I've done
> almost nothing online... once you go high speed, turning back to dialup
> is just too painful!)

Welcome to the joys of SSH2. The DH in that message is "Diffie-Hellman"
which is a form of public-key key negotiation. It is also computationally
expensive. It annoys me on my Beige G3, so I expect it'd be DANG slow on a
mac68k.

One difference might be that the size of the exchange is negotiatble, and
that MacOS X is negotiating a bigger key size than the other ssh v2
products.

Take care,

Bill