Can no longer connect via ssh

[TygerTung]

Hi,

I installed Debian 9 onto an old HP Thin Client to use as a PiHole DNS server. I had to thin it out a bit as there is only a 1GB flash drive. I only installed ssh as an optional extra over the base system.

After getting the pi-hole up and running I can no longer log into the machine using ssl. It doesn't appear on the DHCP table, but maybe that is because I have given it a fixed IP address so that it works as a DNS server.

If I ping its IP address it responds.

When I try to log in this happens:

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sam@sam-1215P:~$ ssh 192.168.1.5
ssh: connect to host 192.168.1.5 port 22: Connection refused

It is preferable to be able to get into the machine remotely, so I don't need a monitor and keyboard hooked up at all times.

Cheers,

Sam

[RU55EL]

What account are you trying to connect to?

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sam@sam-1215P:~$ ssh sam@192.168.1.5

[TygerTung]

Maybe sam? There is only one account there.

[eriefisher]

What was the user name you set up on that system??? Also you don't need the port if your using the defaults but that's a whole other thing.

[TygerTung]

It is the same username on both machines so previously connected OK.

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ssh sam@192.168.1.5

That returns the same result,

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ssh: connect to host 192.168.1.5 port 22: Connection refused

[eriefisher]

"connection refused"

I the server running on that machine? Have you got the right machine?

[TygerTung]

Yes, it is the correct machine. I fixed the IP address in the router to ensure it wouldn't change.

[sickpig]

is sshd running?

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# systemctl status sshd

[TygerTung]

I checked on both machines; same result:

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sam@sam-1215P:~$ systemctl status sshd
Unit sshd.service could not be found.

[sickpig]

You kinda need sshd on your pihole to be able to ssh into it...

[cuckooflew]

I only installed ssh as an optional extra over the base system.

I am pretty sure openssh-server also needs to be installed.

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# apt install openssh-server

If that still does not work try :

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apt-get purge openssh-server
 apt-get install openssh-server 

There is some more trouble shooting tips here: https://www.ssh.com/ssh/sshd/
========= edit =====
And some minimal search foo will get even more information,
EG: key words:

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installed ssh on Debian, but it says Unit sshd.service could not be found. 

[sickpig]

@OP you might want to consider Dropbear as an alternative to open-ssh if you are storage space challenged.

[cuckooflew]

Also the Debian documentation is very usefull:
https://wiki.debian.org/SSH

Installation of the server

The server allows to connect remotely and gets installed by running as root:

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apt install openssh-server 

I see it mentions "DropBear " as well. as a alternative.

TygerTung » I had to thin it out a bit as there is only a 1GB flash drive. I only installed ssh as an optional extra over the base system.

Rather then struggling and fretting because there is only 1gb available, maybe consider buying another flash drive, but with 10gb, or even 20gb, or more , 32 gb ?
I see some for as low as $5.00, but I guess that depends on what part of the world you are in as well,...

[TygerTung]

It is really surprising that I need to install another package, as yesterday just normal "ssh" was working fine, but today no good?!

I'll try again tomorow.

[sickpig]

could have gotten removed during

I had to thin it out a bit as there is only a 1GB flash drive. I only installed ssh as an optional extra over the base system.

you can check the dpkg logs to ascertain

[cuckooflew]

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sam@sam-1215P:~$ systemctl status sshd
Unit sshd.service could not be found. 

Well, this pretty much speaks for itself, Also this: http://forums.debian.net/viewtopic.php?f=30&t=146981 From the other topic you started, you show this:

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openssh-client install
[b]openssh-server deinstall[/b]
openssl install 

in your list. You know "deinstall", means remove ? It is simple, easy, to just check and see if it: (openssh-server ) is installed.

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dpkg --list | grep ssh 

If it does not show in the list, you need to install it, if it is in the list, you need to look at some other things, check to see if it even is installed first.

I'll try again tomorow.

Unless you change something between.today and tomorrow, it will be the same tomorrow as it is today, EG: install openssh-server today, and it will work again tomorrow.
If everything you need won't fit on a 1gb, flash stick, then you simply need to get a bigger one. Remove other things, will just succeed in breaking something else, eg; foo package , but foo package includes dependencies that foo2 package needs, you need to have enough drive space for all of the essential programs/packages. + some extra.. Even a Minix3 server needs at least 1.2gb to be functional, Debian is going to need more space, even if it is just the base (minimal install)

[cuckooflew]

Here is what a working ssh server looks like , using the commands posted in the previous posts:

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cuckoo@debian:~$ systemctl status sshd
* ssh.service - OpenBSD Secure Shell server
   Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2020-08-04 09:03:04 CDT; 5h 9min ago
     Docs: man:sshd(8)
           man:sshd_config(5)
  Process: 412 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
 Main PID: 425 (sshd)
    Tasks: 1 (limit: 1141)
   Memory: 2.4M
   CGroup: /system.slice/ssh.service
           `-425 /usr/sbin/sshd -D 

======================

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cuckoo@debian:~$dpkg --list | grep ssh 
ii  libssh-gcrypt-4:amd64                0.8.7-1+deb10u1                     amd64        tiny C SSH library (gcrypt flavor)
ii  libssh2-1:amd64                      1.8.0-2.1                           amd64        SSH2 client-side library
ii  openssh-client                       1:7.9p1-10+deb10u2                  amd64        secure shell (SSH) client, for secure access to remote machines
ii  openssh-server                       1:7.9p1-10+deb10u2                  amd64        secure shell (SSH) server, for secure access from remote machines
ii  openssh-sftp-server                  1:7.9p1-10+deb10u2                  amd64        secure shell (SSH) sftp server module, for SFTP access from remote machines
ii  task-ssh-server                      3.53                                all          SSH server

 

[debianneedstuning]

FWIW; When I recently had this problem after a version upgrade on a headless server, I was unable to fault find and in the end I apt-get remove'd openssh and openssh-server and reinstalled them. Just my 2c.