Why am I getting a "port 22: Connection refused" error?

Question

I am getting a

port 22: Connection refused

error while connecting to a server.

I have both the openssh client and server installed, and they are running. But still there is an error. Please help.

Check ssh is running on port 22 and if you have a firewall rule blocking the port. — Manula Waidyanatha, Nov 17 '12 at 03:46
According to me , Configure firewall such that it allows to ssh (port 22 ) which is currently blocked by firewall. — KK Patel, Nov 17 '12 at 03:53
sudo ufw enable http://askubuntu.com/questions/417998/why-ubuntu-firewall-not-showing-verbose — , May 26 '16 at 04:38
This could occur probably because of temporary network loss too. So check your internet connection. — user648610, Jan 30 '17 at 16:43
This might be useful if you were to explain how to do what you suggest. As is, not so much. Related: http://www.linuxjournal.com/content/troubleshooting-telnet — Elder Geek, Jan 30 '17 at 17:57
I can't seem to answer for some reason. But I had the same issue working with MAC M1, for me the solution was changing the system setting through system preferences as described here: https://superuser.com/a/190610/917327 — Shefy Gur-ary, Feb 14 '22 at 13:43

score 118 · Answer 1 · edited Apr 29 '18 at 20:09

118

I went through this issue and finally got appropriate answer.

sudo apt-get update
sudo apt-get install openssh-server
sudo ufw allow 22

Then went into raspi-config in a terminal window and enabled ssh.

This will allow port 22 to be used for sshd.

edited Apr 29 '18 at 20:09

SDsolar

3,169

answered Aug 14 '15 at 13:50

Doogle

1,281

Same problem here as @SDsolar – Nathan B Apr 29 '18 at 11:23
@Nadiv, I also had to use raspi-config to enable ssh. Answer has been edited to reflect this. – SDsolar Apr 29 '18 at 15:50
1

Performed the first three lines on both computers and the file is now successfully transferred. Why does Ubuntu not come with these installed/enabled by default? The connection refused error is so cryptic, I had no idea if it was a firewall issues, username issue, IP address issue, etc etc. Very frustrating. – Hatefiend Jun 20 '19 at 01:53
sudo ufw allow 22 worked once. Again the error started appearing. – vineeshvs Sep 05 '19 at 07:57

score 36 · Answer 2 · edited Nov 17 '12 at 04:54

36

While on the server, check to make sure sshd is actually running, and is listening on port 22:

$ sudo netstat -anp | grep sshd
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1538/sshd       
tcp6       0      0 :::22                   :::*                    LISTEN      1538/sshd

If you don't get results, or they don't show you're listening on tcp 0.0.0.0:22... fix that.

If you DO show that sshd is running and is listening on tcp port 22, check to make sure there's no firewall rule getting in the way. Again, on the server:

$ sudo iptables -L | grep ssh
DROP       tcp  --  anywhere             anywhere            tcp dpt:ssh

Or alternately,

$ sudo ufw verbose
Status: active

To                         Action      From
--                         ------      ----
22                         DENY        Anywhere
22/tcp                     DENY        Anywhere

If you do see a rule like one of the ones above, you'll need to fix that.

If you don't see any firewall rules in the way and you do see the service running on the server, then it's time to check your workstation, and the network it's connected to. Can you connect to other servers? Can you ping your own interface or loopback address? Etc.

edited Nov 17 '12 at 04:54

belacqua

23,120

answered Nov 17 '12 at 04:44

Jim Salter

4,343

1

and if you can connect to other servers? – OpenCoderX Apr 25 '13 at 20:43
2

Hey thanks for answer, mine is not port 22, its 2222. You said, fix that, but how? – Yogesh D Mar 11 '17 at 18:50
Mine gave no results. – SDsolar Jun 23 '17 at 21:20
fix it with: sudo ufw allow 22 (or whatever your port is) – John D Jan 19 '18 at 04:50
No firewall rules in the server. But still SSH is allowed from the PCs in the local network and not from outside our lab (but in the same institute network) – vineeshvs Sep 05 '19 at 07:59
I still can't connect. Is iptables interferring with ufw? – chovy Dec 19 '21 at 20:11

PJunior · Answer 3 · 2014-01-05T13:30:39.503

16

Try this

sudo apt-get remove openssh-client openssh-server

and then

sudo apt-get install openssh-client openssh-server

it worked for me :)

Probably not the most orthodox solution... :)

edited Jan 05 '14 at 13:30

answered Jan 05 '14 at 12:44

PJunior

335
1
3
13

3

Using dpkg-reconfigure would possible be easier to use in lieu of an uninstall/reinstall solution – Stephen Michael Kellat Feb 23 '14 at 04:06
1

I had to use apt-get purge openssh-server (instead of remove) to get it to work. – 11101101b May 14 '16 at 15:01

score 8 · Answer 4 · answered Dec 22 '16 at 20:07

8

Came across same problem after installing Raspbian. Solution that worked for me:

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

answered Dec 22 '16 at 20:07

Wouter

91

If this worked you must have changed your sshd-config before. – guntbert Dec 22 '16 at 21:29
I edited sshd_config on Raspbian while trying to setup ssh. This solution worked for me. – Scott Jan 09 '17 at 20:45
+1. Only solution that worked! – Nathan B Apr 29 '18 at 11:29

score 5 · Answer 5 · edited Dec 26 '17 at 11:32

5

The following commands worked for me:

cd /root/.ssh
vi known_hosts

Now delete everything in that file and enter on the terminal:

service sshd restart

Source: SSH - Connection Refused

edited Dec 26 '17 at 11:32

Martin Thornton

5,431

answered Dec 26 '17 at 11:03

Sruthil Lal S.B.

123

similar problem for me, but I cleared my known_hosts with ssh-keygen -f "/home/MYUSER/.ssh/known_hosts" -R MYHOST, substituting in my linux user and remote host I was trying to connect to – Chris Apr 20 '18 at 16:52
What are known_hosts and why does knowing some hosts prevent the machine from connecting? – Yan King Yin Mar 12 '23 at 16:48

score 2 · Answer 6 · edited Nov 30 '19 at 00:08

2

The static IP was wrong in my case. Found out by doing ping <my_ip> after switching off the server. It was still pinging even when the server was off. Correcting the IP solved the issue.

edited Nov 30 '19 at 00:08

Sunanda

113
5

answered Sep 05 '19 at 08:15

vineeshvs

222
2
8

score 1 · Answer 7 · answered Mar 22 '19 at 08:04

1

This might fix it for you as well. Try port forwarding connection 22 from your outgoing IP address to your local IP on the same port. Worked for me allowing me to ssh in to remote ubuntu computer.

answered Mar 22 '19 at 08:04

jackw11111

794

Why am I getting a "port 22: Connection refused" error?

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