OpenSSH is an open-source version of the Secure Shell (SSH) protocol that can be used to login remotely to a server and to control remote Linux-based systems.
OpenSSH provides secure encrypted communication between two untrusted hosts over an insecure network.
OpenSSH also provides sftp and sftp-server that implement an easier solution for file-transfer and is used in major network monitoring tools and web servers all around the world.
In this tutorial, we will show you how to troubleshoot “the SSH Connection Refused” error while connecting to Ubuntu/Linux.
- Remote Desktop for Mac and Windows to shut down your Pi from a remote device open terminal and type sudo shutdown -h now Xrdp server setup My Pi playlist is.
- Remote Desktop Connection cannot verify the identity of the computer that you want to connect to. Download the Microsoft Remote Desktop app from the Mac App Store and use the app to connect to your instance. RDP displays a black screen instead of the desktop. Try the following to resolve this issue.
- Get the Remote Desktop client. Follow these steps to get started with Remote Desktop on your Mac: Download the Microsoft Remote Desktop client from the Mac App Store. Set up your PC to accept remote connections. (If you skip this step, you can't connect to your PC.) Add a Remote Desktop connection or a remote resource.
Select “All users” to let anyone with a user account on your Mac share your screen. Select “Only these users,” click the Add button, then select the users who can share your Mac. Click Computer Settings, then select options for your Mac. If people connect using a VNC viewer, you need to set a password.
Connecting to a Server Via SSH
There are two ways to connect to a server via SSH. You can either use SSH command or Putty (or any other SSH Client for that matter) to connect a server.
Connect to a Server with SSH command
The basic syntax of the SSH command is shown below:
ssh Username@Server-ip-address -p Port
Where:
- Username : user account on your server.
- Server-ip-address : IP address or Domain name of your server.
- Port : It is the port number of the OpenSSH server, usually 22, unless you’ve changed it.
For example, let’s connect a remote server with username vyom, IP address 192.168.0.102 and Port number 22:
ssh vyom@192.168.0.102 -p 22
When your connecting your server via SSH for the first time, you should see the following message:
The authenticity of host '192.168.0.102 (192.168.0.102)' can't be established.
ECDSA key fingerprint is f7:9c:72:63:33:ac:d6:49:26:9c:af:c6:ff:11:27:01.
Are you sure you want to continue connecting (yes/no)? yes
Type yes and hit Enter , you will be asked to provide a password for user vyom. Provide a password and hit Enter to connect to a server. You should see the following output:
Welcome to Ubuntu 14.04.6 LTS (GNU/Linux 3.19.0-80-generic x86_64)
* Documentation: https://help.ubuntu.com/
Last login: Fri Nov 1 11:36:07 2019 from 192.168.0.102
You should see the above output in the following screen:
Connect a Server with Putty
Putty is open source SSH client software used to connect SSH server from Windows-based operating systems. You can download the Putty software from the Putty download page.
Once downloaded, double-click on the putty.exe program to launch the application. You should see the following screen:
Now, provide your SSH server IP-address, Port number, Connection type and click on the Open button to start the SSH session. If you are connecting to this server first time. You should see the following screen:
Click on the Accept button. You should see a terminal prompt asking for your username.
Provide your username, password and hit Enter to logged into your server.
Troubleshoot SSH Connection Refused
Sometimes you receive an error like “Network error: Connection refused” while connecting to your server via SSH. There are a number of reasons for this error. In order to fix this error, you will need to identify the cause of the error by checking and ruling out each possibility. In this section, we will show you some troubleshooting steps to resolve this error.
Step 1
First, make sure the openssh-server package is installed on your server.
You can check it with the following command:
dpkg -l | grep openssh-server
If the openssh-server is installed, you should see the following output:
ii openssh-server 1:6.6p1-2ubuntu2.13 amd64 secure shell (SSH) server, for secure access from remote machines
If not installed, you can install it with the following command:
apt-get install openssh-server
Step 2
OpenSSH service uses sshd daemon to listen to the incoming connections and handles user authentication. If this service crashes, the connection fails and you will get the SSH Connection refused error.
You can check the status of OpenSSH service whether it is running or not with the following command:
/etc/init.d/ssh status
If it is running, you should see the following output:
ssh start/running, process 5476
You can also check the SSH service with the following command:
ps -ef | grep ssh
You should see the following output:
vyom 4651 4407 0 09:19 pts/0 00:00:00 ssh vyom@192.168.0.102 -p 22
root 4652 1 0 09:19 ? 00:00:00 sshd: vyom [priv]
vyom 4782 4652 0 09:20 ? 00:00:00 sshd: vyom@pts/18
root 5167 1 0 09:32 ? 00:00:00 sshd: vyom [priv]
vyom 5229 5167 0 09:33 ? 00:00:00 sshd: vyom@pts/27
root 5476 1 0 09:46 ? 00:00:00 /usr/sbin/sshd -D
vyom 5532 3678 0 09:50 pts/15 00:00:00 nano New/New/SSH/ssh
root 5584 5410 0 09:54 pts/18 00:00:00 grep --color=auto ssh
If an OpenSSH service is not running, you can start it with the following command:
/etc/init.d/ssh start
You should see the output of the above commands in the following screen:
Step 3
By default, OpenSSH is running on port 22 and is vulnerable to attack. Sometimes you’ll get the “Network error: Connection refused” error if your SSH server is listening on a different port.
First, you will need to find the open ports in your server with Nmap command:
nmap 192.168.0.102
You should see the following output:
Starting Nmap 6.40 ( http://nmap.org ) at 2019-12-05 10:03 IST
Nmap scan report for 192.168.0.102
Host is up (0.00016s latency).
Not shown: 998 closed ports
PORT STATE SERVICE
2200/tcp open ici
7070/tcp open realserver
Nmap done: 1 IP address (1 host up) scanned in 2.09 seconds
In the above output, you should see that port 2200 and 7070 are open on your server.
Now, check which service is running on the given ports (2200, 7070) one by one:
nc -v -nn 192.168.0.102 2200
You should see that SSH service is running on port 2200:
Connection to 192.168.0.102 2200 port [tcp/*] succeeded!
SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.13
You can also check the OpenSSH listening port by opening the file:
/etc/ssh/sshd_config
You should now be able to connect to your OpenSSH server using the port 2200 as shown below:
ssh vyom@192.168.0.102 -p 2200
You should see the output of all the commands in the following screen:
Step 4
Some times you will get the “Network error: Connection refused” error, if your OpenSSH server IP address is conflict with other systems in your network.
You can use arp-scan tool to check the duplicate IP address in your network as shown below:
Microsoft Remote Desktop For Mac Connection Refused Invalid
arp-scan 192.168.0.0/24
You should see the following output:
Interface: enp0s3, datalink type: EN10MB (Ethernet)
Starting arp-scan 1.9 with 256 hosts (http://www.nta-monitor.com/tools/arp-scan/)
192.168.0.1 c8:3a:35:59:49:b0 Tenda Technology Co., Ltd.
192.168.0.102 4c:bb:58:9c:f5:55 (Unknown)
192.168.0.103 4c:bb:58:9c:f5:55 (Unknown)
192.168.0.104 4c:bb:58:9c:f5:55 (Unknown)
192.168.0.102 98:74:da:e5:6b:55 (Unknown) (DUP: 2)
10 packets received by filter, 0 packets dropped by kernel
Ending arp-scan 1.9: 256 hosts scanned in 2.082 seconds (122.96 hosts/sec). 6 responded
To resolve this error, you will need to change your server’s IP address.
Step 5
Similarly, SSH connectivity problems may occur due to improper firewall configurations. If a firewall is configured to deny SSH connection on your server, the connectivity can fail and lead to the error SSH connection refused.
You can check whether your server is filtered with a firewall or not with the following command:
nmap 192.168.0.102
You should see that your server is filtered with a firewall:
Starting Nmap 6.40 ( http://nmap.org ) at 2019-12-05 10:14 IST
Nmap scan report for 192.168.0.102
Host is up (0.0012s latency).
All 1000 scanned ports on 192.168.0.102 are filtered
MAC Address: 08:00:27:29:E9:91 (Cadmus Computer Systems)
Nmap done: 1 IP address (1 host up) scanned in 23.57 seconds
To resolve this error, you will need to allow your SSH port through the firewall on your server.
Conclusion
In the above article, we learned how to troubleshoot the “SSH connection refused” error with several examples. I hope you have now enough knowledge to resolve this type of error.
Looking for the best remote desktop app for Mac running OS X Mavericks? Look no further because here we are going to explore 3 of my favorite ways to remote into Windows machines from Mac.
When I purchased my first Apple computer (13″ Macbook Air) early in 2013, I found myself searching for the best application to remote into my Windows computers and servers.With the need for me to be able to quickly remote into a variety of Windows servers, I wanted an RDP client I could use on my Mac that would give me a great experience.
At work we typically suggest Microsoft’s Remote Desktop for Mac to our Doctors and staff when they come to us for assistance with setting up VPN and remote access into the hospital.
But Microsoft’s Remote Desktop for Mac isn’t the only application available.
My RDP Requirements
Since I work heavily on Windows machines, there were a few essential requirements I was looking for to help my overall daily workflow:
- Performance.
- Manageability of multiple systems.
- Price
1. Microsoft Remote Desktop for Mac
Coming in at # 1 for my favorite remote desktop client for Mac is Microsoft’s Remote Desktop for Mac.
Microsoft had recently made version 8.0.0 available. This version really has stepped it up a notch from their previous version.
Performance
Performance is not an issue for me during my tests.
Manageability of multiple systems
Yes, you can manage multiple systems.
One of the biggest notable changes I found with this version over the previous is the fact that you can save client servers/sessions. This was important to me since I have a wide-range of servers that I need to connect to at any moment.
Price
Free
Cons
None as of this writing.
2. 2X Client for RDP/Remote Desktop
Coming in at # 2 on my list is 2X Client for RDP/Remote Desktop.
I have to be honest and say that I haven’t given this one a full blown test as of yet. However, I have used it many times on IOS devices and has worked well. I did install it for my testing here in this article and overall was a nice experience.
I would have to rank this one a close 2nd to Microsoft’s client.
Performance
Overall performance was not an issue for me during my tests.
Manageability of multiple systems
Yes, you can manage multiple systems.
Price
Free
Cons
A small issue I see (and probabaly not an issue for most) is the Windows Snap feature. It seems to be a ‘hit-and-miss’ when I try to snap a window to the top of the screen.
3. CoRD
Coming in at # 3 on my lis is CoRD.
CoRD is a Mac OS X remote desktop client for Microsoft Windows computers.
As of this writing, CoRD’s website has an announcement saying: “Cord don’t seem to work on 10.9 Mavericks. Check back next week.” This was announced on 2013-10-23.
As you can see in the video, I have installed CoRD on my Macbook Air running 10.9 OS X Mavericks and it does work. Maybe there are some bugs that I am not aware of but overall it does seem to run OK for me.
Performance
Overall performance for me was not an issue during my tests.
Manageability of multiple systems
One thing I really do like about CoRD is the option to view all remote sessions in one window. This really saves space on your desktop and makes it a breeze to switch between the different sessions.
Price
Free
Cons
CoRD doesn’t appear to work with NLA (Network Level Authentication). This is a problem for me since a lot of the servers at work are now configured to use NLA, I simply get an error saying: “The requested session access is denied” when I try to connect.
As with CoRD, another issue is the Windows Snap feature is a hit-and-miss.
Conclusion
Microsoft Remote Desktop For Mac Connection Refused Working
In the end, all three of the applications worked well. The major downside for me with CoRD is the fact I am unable to connect to servers with NLA enabled.
For now, I will continue to use Microsoft Remote Desktop for Mac.
I will update this post and/or comments below with any updated experiences (good or bad).
Question for You
Microsoft Remote Desktop For Mac Connection Refused Windows 7
What do you use on your Mac to remotely manage Windows machines?