Re: ssh-ing in inside private network

[Stephen Powell <zlinuxman@fastmail.com>]

On Tue, May 31, 2016, at 15:31, Lisi Reisz wrote:
> ...
> So I need static IPs fast!
> ...

(The above was actually quoted from an earlier post).
If you want to convert your computers to use static IP addresses, you might
want to take a look at the following web page:

   http://www.stevesdebianstuff.org/hercules.htm

The main subject of the web page is running Debian under Hercules under Debian,
which of course you are not interested in.  But in the process of documenting
that there is a discussion about converting the host system for Hercules to use
a static IP address.  Using static IP addresses has some little known
"gotchas", which are covered above.  See the section titled "Networking
changes".  It also covers switching from network-manager to ifupdown, but if
I recall correctly, you've already made that conversion.

You might also want to take a look at the section titled "Router
reconfiguration".  In your case, you probably don't need or want to reconfigure
the router, but you might want to get into the reconfiguration screens so that
you can find out for sure which addresses are in the router's DHCP pool,
so that you can chose a static IP address which is *inside* the router's
network but *outside* the DHCP pool.  That way, you can be sure that your
static IP address will never interfere with what DHCP wants to do.

>
> Help!!  This was the point of the whole exercise.  I want CLI only (no X 
> running) access to the Ubuntu installation on Hermes.
> 

Ubuntu systems usually do not have a password assigned to root.  Therefore,
you have to use sudo for all administrative work.  If you want to *be* root,
so that all commands issued run with root privileges, you have to assign
a password to root with

   sudo passwd root

I recommend that you ssh into the machine as a non-root user first, then
elevate privileges by running a nested root shell via

   su

After you supply the root password, which you just set earlier, your
privileges will be escalated to root privileges until you enter the

   exit

command, which will return you to your former non-root self.  It is possible
to login remotely as root, if the configuration of the host system's ssh
server allows it, but "best practices" recommends against it for security
reasons.  It makes your home network easier to hack.  But if you really
want to do it, edit the file /etc/ssh/sshd_config.  In the

   # Authentication

section, look for

   Permitrootlogin no

and change it to

   Permitrootlogin yes

then bounce the ssh daemon with

   /etc/init.d/ssh restart

As I said, it's not recommended;
but it's your gun, your bullet, and your foot!

-- 
  .''`.     Stephen Powell    <zlinuxman@fastmail.com>
 : :'  :
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   `-