How to Connect to a Server via SSH: PuTTY & OpenSSH Guide

SSH (Secure Shell) is the most common way to manage your VDS. This guide covers connecting with PuTTY on Windows and OpenSSH on Linux/macOS, plus setting up SSH keys.

Connection details

Your KavesNET server delivery email contains:

• IP address (e.g., 192.168.1.100)
• Username (usually root)
• Password
• Port (default 22)

Windows: connect with PuTTY

1. putty.org → download putty.exe
2. Open → Host Name: your-IP → Port: 22 → Connection type: SSH → Open
3. First connection shows “Server’s host key” warning → Accept
4. login as: root → paste your password (Right-click = paste)

Once connected, the terminal opens and you can run commands.

Linux / macOS: OpenSSH

Built-in. Open Terminal:

ssh [email protected]

Custom port:

ssh -p 2222 [email protected]

First connection asks for fingerprint → yes. Then password, you’re in.

Passwordless login with SSH keys (recommended)

SSH keys are both more secure and faster than passwords.

1. Generate a key pair (on your local machine)

Linux/macOS:

ssh-keygen -t ed25519 -C "kaves@laptop"
# Enter, Enter (passphrase optional)

Windows (PowerShell or PuTTYgen): Open PuTTYgen → Type: ED25519 → Generate → move mouse → Save private key (.ppk)

2. Copy public key to server

Linux/macOS:

ssh-copy-id [email protected]

Manual (when PuTTY or ssh-copy-id isn’t available):

# On the server
mkdir -p ~/.ssh && chmod 700 ~/.ssh
echo "PUBLIC_KEY_CONTENTS" >> ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys

3. Test it

ssh [email protected]
# Should connect without asking for a password

In PuTTY: Connection → SSH → Auth → Credentials → Browse → select your .ppk → Save session.

Disable password login (security)

Once SSH keys are working, disable password login:

sudo nano /etc/ssh/sshd_config

Change these lines:

PasswordAuthentication no
PermitRootLogin prohibit-password

Save → sudo systemctl restart ssh. Now only SSH keys work — brute-force impossible.

Common errors

• “Connection refused”: SSH service is off or port wrong → on server sudo systemctl status ssh
• “Permission denied (publickey)”: Key not copied to server or wrong user
• “Host key verification failed”: Reinstalled server, fingerprint changed → ssh-keygen -R 192.168.1.100
• Slow connection: DNS lookup → in /etc/ssh/sshd_config set UseDNS no

Pro tips

• Create an alias in ~/.ssh/config:

  Host vds
    HostName 192.168.1.100
    User root
    Port 22
    IdentityFile ~/.ssh/id_ed25519

  Then just ssh vds works.

• Install fail2ban — auto-bans IPs after 5 failed attempts

• Use a custom port (e.g., 22 → 2222) — reduces bot scans

Conclusion

SSH keys + disabling password auth is the foundation of server security. A 5-minute task for lifetime security.

Related: UFW Firewall · Plesk Installation