How to troubleshoot issues with firewall basics (ufw, firewalld)?

This guide provides essential tips on troubleshooting issues with Linux firewalls like UFW (Uncomplicated Firewall) and Firewalld. Learn how to resolve connectivity problems, check firewall status, and understand log management for effective firewall administration.

Linux Firewall Troubleshooting, UFW, Firewalld, Connectivity Issues, Firewall Status

When dealing with firewall issues, consider the following steps to troubleshoot effectively:

  1. Check Firewall Status: Ensure the firewall is active and correctly set up.
  2. List Rules: Review the current rules to see if any are causing the issue.
  3. Test Connectivity: Use tools like ping or telnet to check connectivity.
  4. Examine Logs: Investigate log files to find any blocked connections.
  5. Adjust Rules: If necessary, modify or add rules to allow the desired traffic.

Here’s an example of how to check the UFW status and list the rules:

# Check UFW status sudo ufw status verbose # List UFW rules sudo ufw status numbered

For Firewalld, you can check the status and rules with the following commands:

# Check Firewalld status sudo firewall-cmd --state # List Firewalld rules sudo firewall-cmd --list-all

Linux Firewall Troubleshooting UFW Firewalld Connectivity Issues Firewall Status

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