How to start SSH daemon in Ubuntu?

Roxxor2 · 03-21-2006, 06:33 AM

How do I start SSH server?

I have emigrated from Gentoo (Im still using it too by the way) and there I just have to start sshd. But there is not sshd program so my quesition is how I start a ssh dameon so I can connect to this computer.

I just have /etc/init.d/ssh
not sshd (as in Gentoo).

I have run

Code:

sudo apt-get install ssh

and

Code:

sudo apt-get install openssh-server

What's wrong?

Wells · 03-21-2006, 09:39 AM

On gentoo, the /etc/init.d/ssh startup script IS the sshd startup script. You should just have to do an "/etc/init.d/ssh start" and sshd should be running.

Roxxor2 · 03-21-2006, 11:22 AM

Ok, here I go:

Code:

roxxor@laptop:~$ sudo /etc/init.d/ssh start
 * Starting OpenBSD Secure Shell server...               
Could not load host key: /etc/ssh/ssh_host_rsa_key
Could not load host key: /etc/ssh/ssh_host_dsa_key
Disabling protocol version 2. Could not load host key
sshd: no hostkeys available -- exiting.      [fail]

What's wrong and how can I solve it?

Wells · 03-21-2006, 03:17 PM

Looks like the host keys were never generated for some reason. You need to do something along the lines of the following to generate those keys, then restart the service:

ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key -N ""
ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N ""

Roxxor2 · 03-23-2006, 05:50 AM

Code:

roxxor@laptop:~$ sudo ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
Generating public/private rsa key pair.
/etc/ssh/ssh_host_rsa_key already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /etc/ssh/ssh_host_rsa_key.
Your public key has been saved in /etc/ssh/ssh_host_rsa_key.pub.
The key fingerprint is:
xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx root@laptop

Code:

roxxor@laptop:~$ /etc/init.d/ssh start
 * Starting OpenBSD Secure Shell server... Could not load host key: /etc/ssh/ssh_host_rsa_key
Could not load host key: /etc/ssh/ssh_host_dsa_key
Disabling protocol version 2. Could not load host key
sshd: no hostkeys available -- exiting.           [fail]

muha · 03-23-2006, 06:26 AM

Could it be that you aren't root when starting ssh?
try:

Code:

sudo /etc/init.d/ssh start

actually changing user with su first, probably gives you some more info when starting the ssh server.

Roxxor2 · 03-23-2006, 06:28 AM

Then I just get

Code:

roxxor@laptop:~$ sudo /etc/init.d/ssh start
Password:
 * Starting OpenBSD Secure Shell server...       [fail]

EDIT:

I don't know if this is a bug, but look:

Code:

roxxor@laptop:~$ sudo /etc/init.d/ssh start
* Starting OpenBSD Secure Shell server... [fail]
roxxor@laptop:~$ sudo /etc/init.d/ssh restart
* Restarting OpenBSD Secure Shell server... [ ok ]
roxxor@laptop:~$ sudo /etc/init.d/ssh stop
* Stopping OpenBSD Secure Shell server... [ ok ]
roxxor@laptop:~$ sudo /etc/init.d/ssh start
* Starting OpenBSD Secure Shell server... [ ok ]

Any comments?

Got the solution from here: http://www.ubuntuforums.org/showthre...=100934&page=2

Wells · 03-23-2006, 08:20 AM

Well... for that last set of stuff where you are starting and stopping the service, it looks like the following was already occurring:

1st: The sshd daemon was already running, so starting it again fails (Oooh! A smart startup script! Nice!)
2nd: Since it is restarting it, it found the old process, stopped it, then started it again. No problems!
3rd: Hey, it was still running from when you restarted it, so stopping it is no problem now.
4th: Well, you did just stop it in 3, so starting it now works like a charm.

At this point, you should be able to ssh into the machine without issue, since the sshd daemon is running. If you can't, I would say that you have an issue somewhere else, perhaps a firewall or something going on.

muha · 03-24-2006, 07:55 AM

So, how can you tell whether the ssh daemon is running or not? (as root) try

Code:

rcsshd status

Roxxor2 · 03-27-2006, 03:42 AM

Quote:

Originally Posted by muha

So, how can you tell whether the ssh daemon is running or not? (as root) try

Code:

rcsshd status

rcsshd is an unknown command.

Wells · 03-27-2006, 08:30 AM

To see if there is an sshd process running on ANY linux machine, you could try the following:

$ ps -ef | grep ssh

That should show you whether or not there is either an ssh or sshd process running at any given time.