How to Reset Forgotten Ubuntu User Password: 10 Simple Steps

If you’ve ever tried connecting to a Linux server using SSH and been hit with the frustrating message:

ssh: connect to host x.x.x.x port 22: Connection refused

You’re not alone.

This error is one of the most common (and confusing) issues Linux users face, whether they’re system administrators, developers, DevOps engineers, or students learning Linux.

The good news?

In most cases, the issue is simple and completely fixable once you understand what’s going wrong.

In this comprehensive guide, you’ll learn how to fix SSH connection refused error on Linux, step by step. We’ll cover every real-world cause, explain why it happens, and show you exact commands to diagnose and fix it—without unnecessary repetition or fluff.

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What Does “SSH Connection Refused” Actually Mean?

Before fixing the problem, it’s important to understand what the error means.

When you attempt an SSH connection:

ssh user@server_ip

Your system tries to:

1. Reach the remote server over the network
2. Connect to a specific port (default: 22)
3. Communicate with the SSH service running on that server

A “SSH connection refused” error means:

• The server is reachable, but
• Nothing is listening on the specified port, or
• The connection is being actively blocked or rejected

This is different from errors like:

• No route to host (network issue)
• Connection timed out (firewall or routing problem)

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Common Reasons for SSH Connection Refused on Linux

Here are the most common causes you’ll encounter in real environments:

1. SSH service is not running
2. SSH is installed but disabled
3. Incorrect SSH port
4. Firewall blocking SSH
5. SSH configured to listen on localhost only
6. SELinux blocking SSH
7. TCP wrappers or access rules blocking connection
8. Server-side IP restrictions
9. SSH daemon misconfiguration
10. Hosting provider or cloud security group issues

We’ll go through each logically and practically.

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Start with the Basics: Is SSH Even There?

Picture this: You're SSHing from your laptop, but the remote box doesn't have the server side installed. Rookie mistake, but it happens on fresh minimal installs like Ubuntu Server or CentOS Stream.

First, on your local machine (the client), check if you even have the SSH client: just type ssh. If it spits out usage info, you're good. If "command not found," install it quick:

Ubuntu/Debian:

sudo apt update && sudo apt install openssh-client

Fedora/RHEL/CentOS:

sudo dnf install openssh-clients (or yum on older boxes)

Now, the real issue is usually the server side. SSH into localhost on the target machine (via console, VPS panel, or whatever access you have):

ssh localhost

SSH Connection refused?

Yep, no sshd daemon.

Install it:

Ubuntu/Debian: 

sudo apt update && sudo apt install openssh-server

Fedora: 

sudo dnf install openssh-server

RHEL/CentOS/AlmaLinux/Rocky: 

sudo dnf install openssh-server (RHEL 8+; use yum for 7)

Arch: 

sudo pacman -S openssh

Boom, installed. But it won't auto-start on some distros, so enable and fire it up:

sudo systemctl enable --now sshd

(or ssh on Debian/Ubuntu).

Check status: 

sudo systemctl status sshd

Should say "active (running)." If not, we dig deeper next.

How to Fix SSH Connection Refused Error on Linux

Step 1: Confirm Basic Network Connectivity

Before touching the server, make sure your system can actually reach it.

Test with ping

ping server_ip

If ping fails:

• The server may be down
• Network routing may be broken
• ICMP may be blocked (not always a problem)

Test the SSH port directly

nc -zv server_ip 22

Or:

telnet server_ip 22

If you see connection refused, the server is reachable—but SSH isn’t accepting connections.

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Step 2: Check If SSH Service Is Running on the Server

This is the most common cause of the SSH connection refused error on Linux.

Log into the server locally or via console access.

Check SSH service status

sudo systemctl status ssh

Or on older systems:

sudo systemctl status sshd

If the service is inactive or failed, SSH won’t accept connections.

Start SSH service

sudo systemctl start ssh

Enable it at boot:

sudo systemctl enable ssh

Recheck:

sudo systemctl status ssh

If SSH was stopped, this alone may fix the issue.

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Step 3: Install OpenSSH Server (If Missing)

On minimal Linux installations, SSH server may not be installed at all.

Check if SSH server is installed

ssh -V

This checks the client, not the server. To check server:

dpkg -l | grep openssh-server   # Ubuntu/Debian
rpm -qa | grep openssh-server   # RHEL/CentOS

Install OpenSSH server

Ubuntu / Debian

sudo apt update
sudo apt install openssh-server

RHEL / CentOS / Rocky / Alma

sudo yum install openssh-server

Then start the service:

sudo systemctl start sshd

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Step 4: Verify the SSH Port Number

By default, SSH listens on port 22, but many administrators change it for security reasons.

Check SSH listening port

sudo ss -tulpn | grep ssh

Or:

sudo netstat -tulpn | grep ssh

You might see something like:

LISTEN 0 128 0.0.0.0:2222

This means SSH is running on port 2222, not 22.

Connect using the correct port

ssh -p 2222 user@server_ip

If you try port 22 while SSH listens elsewhere, you’ll always get SSH connection refused.

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Step 5: Check SSH Configuration File

The SSH daemon configuration file controls how SSH behaves.

Open sshd_config

sudo nano /etc/ssh/sshd_config

Key settings to verify:

Port

Port 22

Ensure it matches the port you’re connecting to.

ListenAddress

ListenAddress 0.0.0.0

If it’s set to:

ListenAddress 127.0.0.1

SSH will only accept local connections, causing remote attempts to be refused.

Protocol

Protocol 2

Restart SSH after changes

sudo systemctl restart ssh

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Step 6: Check Firewall Rules (Very Common Cause)

Even if SSH is running, a firewall can block access.

Ubuntu / Debian (UFW)

Check status:

sudo ufw status

Allow SSH:

sudo ufw allow ssh

Or specific port:

sudo ufw allow 22/tcp

Reload firewall:

sudo ufw reload

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RHEL / CentOS / Rocky / Alma (Firewalld)

Check firewall:

sudo firewall-cmd --list-all

Allow SSH:

sudo firewall-cmd --permanent --add-service=ssh

Or custom port:

sudo firewall-cmd --permanent --add-port=2222/tcp

Reload:

sudo firewall-cmd --reload

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Check iptables (advanced systems)

sudo iptables -L -n

If port 22 is blocked, you’ll need to add a rule to allow it.

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Step 7: Check SELinux (RHEL-Based Systems)

SELinux can silently block SSH even when everything else looks correct.

Check SELinux status

sestatus

If SELinux is Enforcing, check SSH ports:

sudo semanage port -l | grep ssh

If your SSH runs on a custom port, allow it:

sudo semanage port -a -t ssh_port_t -p tcp 2222

Restart SSH:

sudo systemctl restart sshd

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Step 8: Verify SSH Is Listening on All Interfaces

SSH may be running but bound to the wrong network interface.

Check listening address

ss -tulpn | grep ssh

If you see:

127.0.0.1:22

SSH only listens locally. Fix this in sshd_config:

ListenAddress 0.0.0.0

Restart SSH afterward.

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Step 9: Check TCP Wrappers and Access Rules

Some systems restrict SSH using /etc/hosts.allow and /etc/hosts.deny.

Check hosts.deny

cat /etc/hosts.deny

If you see:

sshd: ALL

SSH connections will be refused.

Fix it

Edit /etc/hosts.allow:

sshd: ALL

Or allow specific IPs.

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Step 10: Verify Cloud Security Groups (AWS, GCP, Azure)

If you’re using a cloud server, local firewall rules are not enough.

Check:

• AWS Security Groups
• Azure NSG rules
• GCP firewall rules

Ensure:

• SSH port is allowed
• Your IP is permitted
• Correct port is configured

Cloud firewalls often cause SSH connection refused even when Linux is configured correctly.

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Step 11: Check SSH Logs for Clues

Logs provide exact reasons for failures.

Ubuntu / Debian

sudo journalctl -u ssh

Or:

sudo tail -f /var/log/auth.log

RHEL / CentOS

sudo tail -f /var/log/secure

Look for:

• Port binding errors
• Permission denied messages
• SELinux denials
• Configuration syntax errors

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Step 12: Restart the Server (Last Resort)

If:

• SSH config is correct
• Firewall rules are correct
• SSH service is running

A reboot can resolve stuck services or kernel-level issues:

sudo reboot

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Final Thoughts

The SSH connection refused error on Linux looks intimidating at first, but in reality, it’s almost always caused by one of a handful of configuration issues. Once you understand how SSH works behind the scenes, fixing it becomes systematic and predictable.

Whether you’re managing a production server, a cloud VM, or a local Linux machine, the steps in this guide will help you confidently diagnose and resolve the issue without guesswork.

For more help, you can visit official Ubuntu documntation.

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