Re: ssh-ing in inside private network
On Wednesday 01 June 2016 14:43:29 Mark Fletcher wrote:
> On Wed, Jun 1, 2016 at 9:10 PM Dan Purgert <dan@djph.net> wrote:
> > Lisi Reisz wrote:
> > > On Tuesday 31 May 2016 23:56:02 Richard Hector wrote:
> > >> On 01/06/16 07:31, Lisi Reisz wrote:
> > >> > Now to do what I really wanted to do all along, and ssh in to run
> >
> > level
> >
> > >> > one as root:
> > >> >
> > >> > lisi@Tux-II:~$ ssh root@192.168.0.5
> > >> > ssh: connect to host 192.168.0.5 port 22: No route to host
> > >> > lisi@Tux-II:~$ ssh lisi@192.168.0.5
> > >>
> > >> Run level one? AKA single user mode? I wouldn't expect to find sshd
> > >> running in single user mode. Without checking, I'm not sure I'd even
> > >> expect networking to be up.
> > >>
> > >> Richard
> > >
> > > Yes, I had come to the conclusion that that was probably the problem.
> > > Networking does appear to be up since nmap found a host having scanned
> > > the ports.
> >
> > You'll need to reset the init script to fire at runlevel 1. Not sure
> > how you go about this in a systemd setup.
> >
> > That being said, the 'init' manpage has the following warning:
> >
> > # On a Debian system, entering runlevel 1 causes all processes to be
> > # killed except for kernel threads and the script that does the killing
> > # and other processes in its session. As a consequence of this, it isn't
> > # safe to return from runlevel 1 to a multi-user runlevel: daemons that
> > # were started in runlevel S and are needed for normal operation are no
> > # longer running. The system should be rebooted.
> >
> > I'm not sure if this holds for systemd-init though.
>
> To add to that, and not to make value judgements, but the point of Runlevel
> 1 is that it is single user mode. The whole point is that there is only one
> person logged in, _via the console_, and no one else can be logged in doing
> anything, and therefore it is safe to perform maintenance like taking disks
> offline to back them up (back in the days when that was the main / only way
> to do it) or other similar maintenance tasks.
>
> So, running the ssh daemon in Runlevel 1 is like, well, like trying to fit
> brake blocks to a tomato. It just doesn't make a lot of sense. I think I
> missed what you were actually trying to do but does it really need to be
> done in Runevel 1? Because Runlevel 1 and remote access to the machine
> aren't concepts that belong in the same sentence, at least without a
> negative.
>
> Sorry, probably not what you wanted to hear but...
What I wanted to do was learn! This is obvious once one thinks about it, but
hitting it was a good way to learn. I shall not forget in a hurry that no
servers are running by default in Run Level 1. I wanted to log in without X
and runlevel 1 has no X.
Thanks for your time and help, Mark and Dan (and Richard, and everyone else,
of course).
Lisi
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