How to Fix SSH Connection Timeout Errors Due to Firewall Rules

The time limit reached error on port 22 (ssh: connect to host ... port 22: Connection timed out) occurs when the destination server's firewall (typically IPTables or UFW on Ubuntu/Debian) silently drops or blocks incoming network packets on port 22, preventing client authentication.

Step-by-Step Solution

1. 1

   Step 1: Diagnose if the SSH port is blocked or closed

   Perform a direct network check towards the server's port from your local terminal to verify if it responds to TCP handshakes:

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   # Check port 22 (SSH) status on your remote server
   nc -zv 192.168.1.100 22
   

   (If the output returns "Connection timed out" or hangs indefinitely, the port is being blocked by a local or cloud network firewall).

2. 2

   Step 2: Allow SSH traffic in UFW (Uncomplicated Firewall)

   If your server uses UFW, explicitly allow secure remote access and reload kernel rules:

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   # Allow incoming TCP traffic on the default SSH port
   sudo ufw allow 22/tcp
   
   # Enable UFW if inactive, then reload active rules
   sudo ufw enable && sudo ufw reload
   

3. 3

   Step 3: Configure explicit rules in IPTables

   If you do not use UFW or need fine-grained rules in raw IPTables, open port 22 directly in your input chain:

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   # Accept incoming TCP packets on port 22
   sudo iptables -A INPUT -p tcp --dport 22 -j ACCEPT
   
   # Save the active rules to persist across system reboots
   sudo iptables-save | sudo tee /etc/iptables/rules.v4