How to resolve 'Connection Refused' error in PuTTY?

Verify the server's SSH service is running (e.g., sudo systemctl status sshd). Check that the port number is correct (default is 22), and ensure your firewall allows SSH traffic.

What should I do if the Host Key has changed?

If PuTTY warns you about a changed host key, the server may have been reinstalled or compromised. Verify the new key fingerprint with the server administrator before accepting it.

How do I fix 'Authentication Failed' in PuTTY?

Verify your username and password. If using key authentication, check the key permissions on the server (chmod 600 ~/.ssh/authorized_keys) and ensure the correct .ppk private key is loaded in PuTTY.

Complete PuTTY Tutorial 2026 – Master SSH & Port Tunnels

Installation

Windows (MSI Installer)

Download the installer from the download page.
Run the .msi file and follow the setup wizard.
All tools (PuTTY, PuTTYgen, PSCP, PSFTP, Plink, Pageant) will be installed.

Windows (Standalone)

Download individual .exe files from the download page. No installation needed — just run directly.

macOS

brew install putty

Linux

# Debian/Ubuntu
sudo apt install putty putty-tools

# Fedora/RHEL
sudo dnf install putty

# Arch Linux
sudo pacman -S putty

Your First SSH Connection

Launch PuTTY.
In the Host Name field, enter your server's hostname or IP.
Set Port to 22 (default SSH port).
Select SSH as the connection type.
Click Open.

On first connection, PuTTY will display the server's host key fingerprint. Verify and accept it.

login as: your_username
[email protected]'s password: ********

Welcome to Ubuntu 24.04 LTS
Last login: Fri Mar 13 10:23:45 2026 from 10.0.0.1
your_username@server:~$

Saving Sessions

Save sessions to avoid re-entering connection details:

Configure your session (hostname, port, settings).
In Saved Sessions, type a name.
Click Save.
Double-click the saved session to connect.

SSH Key Authentication

Generate a key pair with PuTTYgen.
Upload the public key to your server's ~/.ssh/authorized_keys.
In PuTTY, go to Connection → SSH → Auth → Credentials.
Browse for your .ppk private key file.
Save the session and connect.

Port Forwarding

Local Port Forwarding

Access a remote service through a local port:

Connection → SSH → Tunnels:
  Source port: 8080
  Destination: remote-db.internal:3306
  Type: Local
  Click "Add"

This forwards local port 8080 to remote-db.internal:3306 through the SSH tunnel.

Dynamic Port Forwarding (SOCKS Proxy)

Connection → SSH → Tunnels:
  Source port: 1080
  Type: Dynamic
  Click "Add"

X11 Forwarding

Run graphical Linux applications on your Windows desktop:

Install an X server on Windows (e.g., VcXsrv, Xming).
In PuTTY: Connection → SSH → X11 → Enable "X11 forwarding".
Connect to your server and run GUI applications.

SSH Tunneling

SSH tunnels encrypt traffic between your local machine and a remote server. Use cases:

Database access — Securely connect to databases behind firewalls.
Web proxying — Route browser traffic through SSH.
Service access — Reach internal services from outside the network.

PSCP — Secure Copy

PSCP is PuTTY's command-line secure file copy tool:

# Upload a file
pscp C:\local\file.txt user@server:/remote/path/

# Download a file
pscp user@server:/remote/file.txt C:\local\path\

# Copy a directory recursively
pscp -r C:\local\folder\ user@server:/remote/path/

# Using a specific SSH key
pscp -i mykey.ppk file.txt user@server:/path/

PSFTP — Secure FTP

PSFTP provides an interactive SFTP session:

psftp user@server

psftp> pwd
Remote directory is /home/user
psftp> ls
psftp> get remote-file.txt
psftp> put local-file.txt
psftp> cd /var/www
psftp> mget *.log
psftp> quit

Plink — Command-Line SSH

Plink is PuTTY's command-line connection tool, ideal for scripting:

# Run a remote command
plink user@server "ls -la /var/www"

# Interactive session
plink -ssh -i mykey.ppk user@server

# Use saved session
plink -load "My Server" "uptime"

# Port forwarding via command line
plink -L 8080:localhost:80 user@server

Terminal Settings

Font & Colors

Customize via Window → Appearance and Window → Colours:

Font — Change font face and size (default: Courier New, 10pt).
Colors — Customize the 16-color ANSI palette.
Cursor — Block, underline, or vertical bar style.

Scrollback

Set in Window: increase "Lines of scrollback" (default: 2000) for longer terminal history.

Proxy Configuration

Configure at Connection → Proxy:

HTTP — Standard HTTP proxy.
SOCKS 4/5 — SOCKS proxy support.
Telnet — Proxy via Telnet commands.

Troubleshooting

Connection Refused

Verify the server's SSH service is running: sudo systemctl status sshd
Check the port number (default: 22).
Ensure firewall allows SSH traffic.

Host Key Changed

If PuTTY warns about a changed host key, the server may have been reinstalled. Verify the new key fingerprint before accepting.

Authentication Failed

Verify username and password.
Check key permissions on server: chmod 600 ~/.ssh/authorized_keys
Ensure the correct .ppk key is loaded.

Timeout / Network Error

Check network connectivity: ping server.example.com
Increase keep-alive interval: Connection → Seconds between keepalives (set to 30).
Check firewall/proxy settings.