Fix: SSH connection timed out error

The ‘SSH connection timed out’ error occurs when the SSH client cannot establish a connection to the remote server within the default timeout period, typically due to network issues, firewall restrictions, or server unavailability.

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How the Error Happens

This error typically occurs when:

• Network connectivity issues between client and server
• Firewall blocking SSH traffic on port 22
• Remote server is down or overloaded
• Network latency is too high
• SSH daemon not running on remote server
• ISP or corporate firewall restrictions

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Solution 1: Test Network Connectivity

# ✅ Test basic network connectivity
ping remote-server.com

# ✅ Test specific port connectivity
telnet remote-server.com 22
# OR using nc (netcat)
nc -zv remote-server.com 22

# ✅ Test SSH port specifically
nmap -p 22 remote-server.com

# ✅ Check if port 22 is open
telnet remote-server.com 22
# If connection is refused, port might be blocked

# ✅ Trace network path
traceroute remote-server.com
# OR on Windows
tracert remote-server.com

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Solution 2: Increase SSH Timeout Values

# ✅ Connect with increased timeout
ssh -o ConnectTimeout=60 user@remote-server.com

# ✅ Set connection attempts
ssh -o ConnectionAttempts=5 -o ConnectTimeout=30 user@remote-server.com

# ✅ Use multiple options
ssh -o ConnectTimeout=60 -o ConnectionAttempts=3 -o ServerAliveInterval=30 user@remote-server.com

# ✅ Edit SSH config for persistent settings
nano ~/.ssh/config

# ✅ Add timeout configuration
Host remote-server.com
    ConnectTimeout 60
    ConnectionAttempts 5
    ServerAliveInterval 30
    ServerAliveCountMax 3

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Solution 3: Check SSH Service on Remote Server

# ✅ If you have console access to the remote server, check SSH service
# On the remote server:
sudo systemctl status ssh
# OR
sudo systemctl status sshd

# ✅ Start SSH service if not running
sudo systemctl start ssh
# OR
sudo systemctl start sshd

# ✅ Enable SSH service to start on boot
sudo systemctl enable ssh

# ✅ Check if SSH is listening on the correct port
sudo netstat -tlnp | grep :22
# OR
sudo ss -tlnp | grep :22

# ✅ Check SSH configuration
sudo nano /etc/ssh/sshd_config
# Ensure Port 22 is uncommented and correct
# Port 22

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Solution 4: Configure Firewall Settings

# ✅ Check firewall status on remote server
sudo ufw status
# OR
sudo iptables -L

# ✅ Allow SSH through firewall
sudo ufw allow ssh
# OR
sudo ufw allow 22/tcp

# ✅ On CentOS/RHEL
sudo firewall-cmd --permanent --add-service=ssh
sudo firewall-cmd --reload

# ✅ Check local firewall (if applicable)
# On Windows
netsh advfirewall firewall show rule name=all | findstr SSH

# On macOS
sudo pfctl -sr

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Solution 5: Use Alternative SSH Ports

# ✅ If SSH is running on a non-standard port
ssh -p 2222 user@remote-server.com

# ✅ Configure SSH config for custom port
nano ~/.ssh/config

# ✅ Add custom port configuration
Host remote-server.com
    Port 2222
    ConnectTimeout 60

# ✅ Check if SSH is running on alternative port
nmap -p 22,2222,8022 remote-server.com

# ✅ Configure SSH daemon for multiple ports
# Edit /etc/ssh/sshd_config on remote server
Port 22
Port 2222

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Solution 6: Use SSH Through Proxy or Jump Host

# ✅ Use a jump host if direct connection fails
ssh -J user@jump-host.com user@remote-server.com

# ✅ Configure SSH config for jump host
nano ~/.ssh/config

# ✅ Add jump host configuration
Host jump-host
    HostName jump.example.com
    User jumpuser

Host remote-server
    HostName remote-server.com
    User remoteuser
    ProxyJump jump-host
    ConnectTimeout 60

# ✅ Use SOCKS proxy if available
ssh -D 1080 user@accessible-server.com
# Then configure your SSH client to use the SOCKS proxy

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Solution 7: Optimize SSH Configuration

# ✅ Optimize SSH client configuration
nano ~/.ssh/config

# ✅ Add optimized settings
Host *
    ServerAliveInterval 60
    ServerAliveCountMax 3
    TCPKeepAlive yes
    ConnectTimeout 30
    ConnectionAttempts 3

Host remote-server.com
    ConnectTimeout 120
    ConnectionAttempts 5
    Compression yes
    Cipher aes128-ctr

# ✅ Use compression for slow connections
ssh -o Compression=yes -o Cipher=aes128-ctr user@remote-server.com

# ✅ Use different cipher if default fails
ssh -o Ciphers=aes128-ctr,aes192-ctr,aes256-ctr user@remote-server.com

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Solution 8: Check DNS Resolution

# ✅ Test DNS resolution
nslookup remote-server.com
# OR
dig remote-server.com

# ✅ Try connecting with IP address directly
ssh user@192.168.1.100  # Replace with actual IP

# ✅ Add entry to hosts file if DNS is problematic
# On Linux/Mac: sudo nano /etc/hosts
# On Windows: C:\Windows\System32\drivers\etc\hosts
# Add: IP_ADDRESS remote-server.com

# ✅ Flush DNS cache if needed
sudo dscacheutil -flushcache  # macOS
sudo systemd-resolve --flush-caches  # Linux
ipconfig /flushdns  # Windows

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Solution 9: Corporate Network Solutions

# ✅ Check if behind corporate proxy
# Configure proxy in SSH config
nano ~/.ssh/config

# ✅ Use proxy command if needed
Host remote-server.com
    ProxyCommand nc -X connect -x proxy.company.com:8080 %h %p
    ConnectTimeout 60

# ✅ Use VPN if corporate network blocks SSH
# Connect to VPN first, then SSH
openvpn --config company-vpn.ovpn
# Then connect via SSH
ssh user@remote-server.com

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Prevention Tips

1. Monitor connectivity: Regularly test SSH connections
2. Use SSH config: Configure optimal timeout values
3. Maintain servers: Keep SSH services running and updated
4. Check firewalls: Ensure SSH ports are accessible
5. Use monitoring: Set up alerts for server downtime
6. Have backups: Maintain alternative access methods
7. Document networks: Keep network diagrams updated
8. Test regularly: Periodically verify connection paths

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When to Contact Support

Contact your hosting provider or network administrator when:

• Following all troubleshooting steps still results in timeout errors
• Suspected infrastructure issues on their side
• Need to investigate server-side network configurations
• Encountering ISP-specific network restrictions
• Experiencing account-related access problems