Documentation

Connect via SSH

Learn how to securely connect to your VPS using SSH. Complete guide to key authentication, configuration, and troubleshooting.

Prerequisites

Active VPS with SSH service running
SSH client installed on your local machine
VPS IP address or domain name
Valid username and password or SSH keys

SSH Basics

SSH (Secure Shell) is the standard protocol for securely connecting to remote servers. It provides encrypted communication and authentication between your local machine and the VPS.

Why SSH?

Encrypted connection prevents eavesdropping
Secure authentication methods
Works on all major operating systems
Supports file transfers and tunneling

# Check if SSH is installed
ssh -V

# On Windows, you might need to use:
# PowerShell: Get-WindowsCapability -Online | Where-Object Name -like 'OpenSSH*'
# Or install OpenSSH client from Microsoft Store

Password Authentication

The simplest way to connect is using password authentication. This method requires you to enter your VPS password each time you connect.

Basic Connection:

Replace your-username with your actual username
Replace your-server-ip with your VPS IP address
You'll be prompted for your password

# Basic SSH connection with password
ssh your-username@your-server-ip

# Specify a different port (if not using default 22)
ssh -p 2222 your-username@your-server-ip

# Connect with verbose output (for troubleshooting)
ssh -v your-username@your-server-ip

SSH Key Authentication

SSH key authentication is more secure than passwords and allows for passwordless login. This is the recommended method for production servers.

Key Benefits:

No passwords to remember or type
More secure than password authentication
Supports automation and scripts
Keys can be password-protected for extra security

# Generate SSH key pair (on your local machine)
ssh-keygen -t rsa -b 4096 -C "your-email@example.com"

# Press Enter for default location
# Optional: Add a passphrase for extra security

# Copy public key to your server
ssh-copy-id your-username@your-server-ip

# Alternative method - manual copy
cat ~/.ssh/id_rsa.pub
# Copy the output and paste it to ~/.ssh/authorized_keys on server

SSH Configuration

You can customize SSH behavior using configuration files. This allows you to set default options, aliases, and security settings.

Configuration Files:

~/.ssh/config - User-specific configuration
/etc/ssh/sshd_config - Server configuration
~/.ssh/known_hosts - Known host keys

# Create SSH config file
nano ~/.ssh/config

# Add server configuration
Host myserver
    HostName your-server-ip
    User your-username
    Port 22
    IdentityFile ~/.ssh/id_rsa

# Now you can connect with:
ssh myserver

# Server-side security (run on your VPS)
sudo nano /etc/ssh/sshd_config

# Recommended security settings:
# Port 22 (change to custom port)
# PermitRootLogin no
# PasswordAuthentication no
# PubkeyAuthentication yes
# MaxAuthTries 3

sudo systemctl reload sshd

Advanced SSH Features

SSH offers many advanced features for power users and administrators. These features can improve productivity and security.

Useful Features:

Port forwarding - Tunnel traffic through SSH
SCP/SFTP - Secure file transfers
SSH agent - Manage multiple keys
X11 forwarding - Run GUI applications remotely

# Port forwarding examples
# Local port forwarding (access remote service locally)
ssh -L 8080:localhost:80 your-username@your-server-ip

# Remote port forwarding (expose local service remotely)
ssh -R 8080:localhost:3000 your-username@your-server-ip

# File transfer with SCP
scp file.txt your-username@your-server-ip:/path/to/destination/
scp your-username@your-server-ip:/path/to/file ./local/destination/

# SFTP for interactive file transfer
sftp your-username@your-server-ip

# SSH agent for managing keys
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_rsa

# Run command remotely without interactive shell
ssh your-username@your-server-ip "sudo apt update && sudo apt upgrade -y"

Troubleshooting SSH

Common SSH connection issues and their solutions. Most problems can be resolved with these troubleshooting steps.

Common Issues:

Connection refused or timeout
Permission denied errors
Host key verification failed
Port already in use

# Check SSH service status on server
sudo systemctl status sshd
sudo systemctl enable sshd
sudo systemctl start sshd

# Test connection with verbose output
ssh -v your-username@your-server-ip

# Clear known hosts (if host key changed)
ssh-keygen -R your-server-ip

# Check firewall settings
sudo ufw status
sudo ufw allow ssh

# Check SSH port
sudo netstat -tlnp | grep :22
sudo ss -tlnp | grep :22

# Test from another location (to rule out network issues)
ssh -T your-username@your-server-ip

Contents

Related Docs

Install Applications

Install and configure applications on your VPS

Firewall Setup

Configure firewall rules to secure your SSH connection

System Updates

Keep your SSH server and client software updated

Need Help?

Can't find what you're looking for? Our support team is here to help.

# Check if SSH is installed ssh -V # On Windows, you might need to use: # PowerShell: Get-WindowsCapability -Online | Where-Object Name -like 'OpenSSH*' # Or install OpenSSH client from Microsoft Store

# Basic SSH connection with password ssh your-username@your-server-ip # Specify a different port (if not using default 22) ssh -p 2222 your-username@your-server-ip # Connect with verbose output (for troubleshooting) ssh -v your-username@your-server-ip

# Generate SSH key pair (on your local machine) ssh-keygen -t rsa -b 4096 -C "your-email@example.com" # Press Enter for default location # Optional: Add a passphrase for extra security # Copy public key to your server ssh-copy-id your-username@your-server-ip # Alternative method - manual copy cat ~/.ssh/id_rsa.pub # Copy the output and paste it to ~/.ssh/authorized_keys on server

# Create SSH config file nano ~/.ssh/config # Add server configuration Host myserver HostName your-server-ip User your-username Port 22 IdentityFile ~/.ssh/id_rsa # Now you can connect with: ssh myserver # Server-side security (run on your VPS) sudo nano /etc/ssh/sshd_config # Recommended security settings: # Port 22 (change to custom port) # PermitRootLogin no # PasswordAuthentication no # PubkeyAuthentication yes # MaxAuthTries 3 sudo systemctl reload sshd

# Port forwarding examples # Local port forwarding (access remote service locally) ssh -L 8080:localhost:80 your-username@your-server-ip # Remote port forwarding (expose local service remotely) ssh -R 8080:localhost:3000 your-username@your-server-ip # File transfer with SCP scp file.txt your-username@your-server-ip:/path/to/destination/ scp your-username@your-server-ip:/path/to/file ./local/destination/ # SFTP for interactive file transfer sftp your-username@your-server-ip # SSH agent for managing keys eval "$(ssh-agent -s)" ssh-add ~/.ssh/id_rsa # Run command remotely without interactive shell ssh your-username@your-server-ip "sudo apt update && sudo apt upgrade -y"

# Check SSH service status on server sudo systemctl status sshd sudo systemctl enable sshd sudo systemctl start sshd # Test connection with verbose output ssh -v your-username@your-server-ip # Clear known hosts (if host key changed) ssh-keygen -R your-server-ip # Check firewall settings sudo ufw status sudo ufw allow ssh # Check SSH port sudo netstat -tlnp | grep :22 sudo ss -tlnp | grep :22 # Test from another location (to rule out network issues) ssh -T your-username@your-server-ip