{"id":3937,"date":"2024-06-11T22:12:53","date_gmt":"2024-06-11T16:42:53","guid":{"rendered":"https:\/\/www.veeble.org\/kb\/?p=3937"},"modified":"2025-04-09T12:05:08","modified_gmt":"2025-04-09T06:35:08","slug":"troubleshooting-ssh-connection-refused-error","status":"publish","type":"post","link":"https:\/\/www.veeble.com\/kb\/troubleshooting-ssh-connection-refused-error\/","title":{"rendered":"Troubleshooting “SSH Connection Refused” Error and Regaining Access"},"content":{"rendered":"\n
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\"Troubleshooting<\/a><\/figure>\n<\/figure>\n\n\n\n

Are you facing the dreaded “SSH Connection Refused” error while trying to access your server? Don’t panic! In this comprehensive step-by-step guide, we will help you troubleshoot the issue and regain access to your SSH connection. In this article, we will walk you through the troubleshooting process, providing easy-to-follow instructions that will help you pinpoint the root cause of the error. From checking your network settings to verifying SSH server configuration, we will cover every possible reason behind the connection refused error.<\/p>\n\n\n\t\t\t\t

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\n\t\t\t\t\t\t\tTable Of Contents\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t
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  1. Checking SSH Credentials<\/a>
  2. Checking Network Connectivity<\/a>
  3. Verifying SSH Server Status<\/a>
  4. Verifying SSH Server Configuration<\/a>
  5. Dealing with Firewall and Port-Blocking Issues<\/a>
  6. Checking SSH Logs<\/a>
  7. Troubleshooting SSH client configuration<\/a>
  8. Reinstalling SSH Service and Restarting the Server<\/a><\/ol>\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\n\n\n

    <\/p>\n\n\n\n

    This common issue can arise due to various reasons, such as SSH authentic failures, network problems, server misconfigurations, or firewall restrictions. Identifying the root cause is crucial to restoring your SSH access. By understanding the typical triggers behind this error, you can streamline the troubleshooting process and expedite the resolution.<\/p>\n\n\n\n

    <\/p>\n\n\n

    Checking SSH Credentials<\/h4>\n\n\n

    The foremost solution is to check the user credentials you tried to connect via SSH into the server were correct. This includes IP address, username, password, and the SSH port. A typo in any of these fields can lead to the server refusing your connection. By double-checking your credentials, you can rule out a simple mistake as the cause of the connection failure. If the credentials are correct, then go ahead with the next steps for resolving the issue.<\/p>\n\n\n\n

    <\/p>\n\n\n

    Checking Network Connectivity<\/h4>\n\n\n

    One of the primary culprits for the SSH connection refused error is incorrect network settings. Ensure that your server is connected to the internet and that no network disruptions are causing the communication breakdown. To check that you can use the Ping tool<\/a> to ping the server first:<\/p>\n\n\n\n

    ping <server ip><\/em><\/code><\/pre>\n\n\n\n
    Replace the <server ip><\/em> with the server IP of your SSH connection issue machine.<\/p>\n\n\n\n
    \n
    \"ping<\/a><\/figure>\n<\/figure>\n\n\n\n
    If you are getting ping like the above picture, it means there are no issues with network connectivity. You can go ahead with the next steps. If the ping to the server IP does not function as expected as in below screenshot, it indicates that the issue lies not with SSH, but with network connectivity, which is beyond the scope of this blog.<\/p>\n\n\n\n
    \n
    \"ping<\/a><\/figure>\n<\/figure>\n\n\n\n
    The next step is to check the connectivity via a specific SSH port to the server. This can be checked with the Telnet tool. For Windows users, you can visit the website https:\/\/portchecker.co\/<\/a> to check if the port is open for connections.<\/p>\n\n\n\n
    telnet<\/span> <hostname_or_IP_address><\/span> <port> <\/span><\/code><\/pre>\n\n\n\n
    Replace <hostname_or_IP_address><\/code> with the hostname or IP address of the server and <port><\/code> with the SSH port you are using for SSH.<\/p>\n\n\n\n
    If the port is open and the SSH service is running, you will see a response similar to this:<\/p>\n\n\n\n
    \n
    \"telnet<\/a><\/figure>\n<\/figure>\n\n\n\n
    If the port is closed or blocked by any firewall rules or misconfiguration inside the server, you will see a response indicating that the connection refused:<\/p>\n\n\n\n
    \n
    \"telnet<\/a><\/figure>\n<\/figure>\n\n\n\n
    <\/p>\n\n\n\n
    To proceed further, you must have access to the server through alternative methods such as physical access, VNC console, IPMI access, or any other means. Without such access, it will not be possible to check or resolve the issue with SSH.<\/p>\n\n\n\n
    <\/p>\n\n\n
    Verifying SSH Server Status<\/h4>\n\n\n
    After reviewing the network connectivity via ping the next step is to check if the SSH service is running on the server. Verifying this fundamental aspect is crucial for an issue related to SSH service.<\/p>\n\n\n\n
    To check if the SSH service is running, access the server via any other methods such as console and execute the following command:<\/p>\n\n\n\n
    sudo systemctl status ssh<\/code><\/pre>\n\n\n\n
    This command will show the status of the SSH service. If it is running, you will see “active (running)” like the below screenshot.<\/p>\n\n\n\n
    \n
    \"check<\/a><\/figure>\n<\/figure>\n\n\n\n
    On some systems, the service might be named sshd<\/code> instead of ssh<\/code>. If the above command doesn’t work for you use: sudo systemctl status sshd<\/code> instead. <\/p>\n\n\n\n
    sudo systemctl status sshd<\/code><\/code><\/pre>\n\n\n\n
    If it is not working, you will see either an inactive status or a disabled status. You can need to enable and activate it by the following commands:<\/p>\n\n\n\n
    sudo systemctl enable ssh\nsudo systemctl restart ssh<\/code><\/pre>\n\n\n\n
    If you encounter any errors while executing commands related to SSH or if you still find the SSH service inactive after executing the above commands, you should check the system logs using journalctl<\/code> for more information about the issue.
    You can view the logs related to SSH via the following command:<\/p>\n\n\n\n
    sudo journalctl -u ssh<\/code><\/pre>\n\n\n\n
    OR<\/p>\n\n\n\n
    sudo journalctl -u sshd<\/code><\/pre>\n\n\n\n
    This command will display log messages related to the SSH service, including any errors or warnings that may help diagnose the issue.<\/p>\n\n\n\n
    <\/p>\n\n\n
    Verifying SSH Server Configuration<\/h4>\n\n\n
    A critical aspect of troubleshooting the SSH connection refused error is examining the server-side configuration settings. Start by reviewing the SSH server’s configuration file, typically at \/etc\/ssh\/sshd_config. Check parameters related to authentication, access controls, and port settings.<\/p>\n\n\n\n
    Inspect the SSH server’s access control rules. Ensure the AllowUsers and AllowGroups directives include the appropriate user accounts and groups for SSH access. Validate the SSH server’s port configuration. SSH typically operates on port 22, but confirm this in the configuration file. If running on a non-standard port, ensure your SSH client connects to the correct port. These adjustments can often resolve connectivity issues and mitigate the SSH connection refused error.<\/p>\n\n\n\n
    Open the SSH server configuration file with a text editor (e.g., nano, vi, or vim) and verify the values you have configured, such as the port number, PermitRootLogin, and PasswordAuthentication. Adjust these settings as needed to ensure they meet your requirements:<\/p>\n\n\n\n
    sudo nano \/etc\/ssh\/sshd_config<\/code><\/pre>\n\n\n\n
    \n
    \"sudo<\/a><\/figure>\n<\/figure>\n\n\n\n
    After verifying and editing the configuration, restart the SSH service with command:<\/p>\n\n\n\n
    sudo systemctl restart ssh<\/code><\/pre>\n\n\n\n
    OR<\/p>\n\n\n\n
    sudo systemctl restart sshd<\/code><\/pre>\n\n\n\n
    <\/p>\n\n\n
    Dealing with Firewall and Port-Blocking Issues<\/h4>\n\n\n
    Firewall restrictions and port blocking issues are common culprits behind the SSH connection refused error, particularly in environments with stringent security policies. Firewalls, both at the server and network levels, can filter incoming connections and block traffic on specific ports, including the default SSH port 22. Resolving firewall and port-blocking issues involves adjusting the firewall rules to permit SSH traffic and unblocking the necessary ports.<\/p>\n\n\n\n
    For this, at first place, you need to check if the SSH daemon is running and listening on the designated port (usually port 22) via system monitoring tools like netstat<\/code> or ss<\/code> . Inorder to check it use one of the tool from it:<\/p>\n\n\n\n
    Using Netstat tool:<\/strong><\/p>\n\n\n\n
    netstat -tuln | grep :22<\/code><\/pre>\n\n\n\n
    \n
    \"netstat<\/a><\/figure>\n<\/figure>\n\n\n\n
    <\/p>\n\n\n\n
    Using SS tool:<\/strong><\/p>\n\n\n\n
    ss -tuln | grep :22<\/code><\/pre>\n\n\n\n
    \"Open<\/a><\/figure>\n\n\n\n
    If there is any output for these commands showing :22 <\/strong>or the SSH port of yours in it, then they are listening and open. If not, then try opening the ports via your firewall.<\/p>\n\n\n\n
    Use the appropriate command for your operating system’s firewalls:<\/p>\n\n\n
    UFW (Ubuntu and Debian-based Linux distributions):<\/h6>\n\n\n
    sudo ufw status<\/code><\/pre>\n\n\n\n
    This command will display the status of the UFW firewall and the list of rules that are configured.<\/p>\n\n\n\n
    How to allow SSH connections via UFW?<\/summary>\n
    To allow SSH connections via UFW on a system running Ubuntu or another distribution that uses UFW, follow these steps:<\/p>\n\n\n\n
    Allow SSH connections in UFW:<\/p>\n\n\n\n
    sudo ufw allow ssh<\/code><\/pre>\n\n\n\n
    Alternatively, you can specify the port number directly (default SSH port is 22):<\/p>\n\n\n\n
    sudo ufw allow 22\/tcp<\/code><\/pre>\n\n\n\n
    Now check the status of UFW to ensure the rule is added:<\/p>\n\n\n\n
    sudo ufw status<\/code><\/pre>\n<\/details>\n\n\n\n
    <\/p>\n\n\n
    IPtables:<\/h6>\n\n\n
    sudo iptables -L<\/code><\/pre>\n\n\n\n
    How to allow SSH connections via IPtables?<\/summary>\n
    To allow SSH connections via iptables<\/code>, you can follow these steps:<\/p>\n\n\n\n
    sudo iptables -A INPUT -p tcp --dport 22 -j ACCEPT\n<\/code><\/pre>\n\n\n\n
    Now save the rules specified now. To save the rules, the command varies with the OS you using.<\/p>\n\n\n\n
    For Debian-based OS like Ubuntu:<\/p>\n\n\n\n
    sudo sh -c \"iptables-save > \/etc\/iptables\/rules.v4\"\nsudo systemctl restart netfilter-persistent<\/code><\/pre>\n\n\n\n
    For RedHat-based OS like Centos:<\/p>\n\n\n\n
    sudo service iptables save\nsudo systemctl restart iptables<\/code><\/pre>\n<\/details>\n\n\n\n
    <\/p>\n\n\n