[ILUG] sshd problem

[Lee Hosty]

On Mon, 19 Apr 2004, Peter McEvoy wrote:

> On Mon, Apr 19, 2004 at 05:57:26PM +0100, Lee Hosty wrote:
> > I have a headless Knoppix hd-install upstairs that I access wirelessly. I
> > don't use it for much except general playing around. As of yesterday I can
> > no longer SSH to it from any of my windows machines. There have been no
> > software or hardware changes on any of these machines in the last week or
> > so - it just suddenly stopped working. sshd is running. I can ssh out from
> > the machine. All machines can ping each other. I've restarted sshd, and
> > rebooted to see if that magically changed anything. iptables has no rules
> > currently. I can ssh from my windows machines to the other world. Other
> > services (samba, slimserver) are working fine.
>
>
> One of the first things I do when having a problem like this is try to
> telnet to the port of the service I'm having trouble with, so in windows
> try "telnet knoppix-host-or-ip 22", you should get the something like:
> Escape character is '^]'.
> SSH-2.0-OpenSSH_3.8p1 Debian 1:3.8p1-2

stays blank for about a minute. eventually time out and gives "Connection
to host lost"

> You should also be looking in /var/log/auth.log to see if you can see

ah. yes. found the problem, I think:

Apr 19 17:47:30 helium sshd[623]: warning: /etc/hosts.allow, line 16:
can't verify hostname:
gethostbyname(rfc1918.space.should.not.be.used.on.publicips) failed
Apr 19 17:47:30 helium sshd[623]: refused connect from 192.168.0.6

As Gavin McCullagh pointed out "something must have changed" :/

It seems /etc/hosts.deny now contains "ALL : PARANOID" which I'm almost
certain wasn't the case a few weeks ago.