Skip to content

Contact sales

By filling out this form and clicking submit, you acknowledge our privacy policy.
  • Labs icon Lab
  • A Cloud Guru
Google Cloud Platform icon

Using 'firewalld' for Advanced Packet Filtering

Managing a local firewall is something pretty much every Linux admin is going to have to do during their career. Many operating systems have adopted firewalld as the local firewall management system moving forward. Setting this up can lead to a more secure server and increase security through your environment.

Google Cloud Platform icon

Path Info

Clock icon Intermediate
Clock icon 1h 0m
Clock icon Nov 12, 2018

Contact sales

By filling out this form and clicking submit, you acknowledge our privacy policy.

Table of Contents

  1. Challenge

    Block SSH but allow HTTP

    Use the block zone to filter on specific hosts and ports.

    You can run the following commands:

    firewall-cmd --zone=block --add-source=

    firewall-cmd --zone=block --add-service=http

    You can verify settings with:

    firewall-cmd --info-zone=block

  2. Challenge

    Allow ping

    Since ping uses the ICMP protocol and not a specific port, we can't just add a port or service.

    We need to use a rich rule:

    firewall-cmd --zone=block --add-rich-rule='rule protocol value="icmp" accept'

The Cloud Content team comprises subject matter experts hyper focused on services offered by the leading cloud vendors (AWS, GCP, and Azure), as well as cloud-related technologies such as Linux and DevOps. The team is thrilled to share their knowledge to help you build modern tech solutions from the ground up, secure and optimize your environments, and so much more!

What's a lab?

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

Provided environment for hands-on practice

We will provide the credentials and environment necessary for you to practice right within your browser.

Guided walkthrough

Follow along with the author’s guided walkthrough and build something new in your provided environment!

Did you know?

On average, you retain 75% more of your learning if you get time for practice.

Start learning by doing today

View Plans