Linux Firewalld & iptables Policy
Firewall rules are one of those Linux skills you can read about for hours and still fumble live. This lab drops you onto a real RHEL host with firewalld and iptables/nftables already installed, so you configure zones and chains against actual traffic instead of a tutorial screenshot.
The problem
A service is supposed to be reachable on its assigned port, and firewalld reports a rule allowing it, but connections from a test client are silently dropped anyway.
What you'll practice
- Configure firewalld zones and assign interfaces/services to them
- Write and order iptables/nftables rule chains by hand
- Open and restrict specific ports and services safely
- Use firewall-cmd runtime vs. permanent configuration correctly
- Diagnose a host that's silently dropping traffic
The topology
A single RHEL host sits between two test clients, so every zone and rule change has an immediately visible effect on real traffic, exactly the setup RHCSA firewall questions assume.
Topology diagram
Frequently asked
Do I need to install RHEL myself?
No. A fully licensed RHEL host with firewalld and iptables/nftables is ready at session start. You configure policy, not the OS.
Is this relevant to the RHCSA exam?
Yes. Firewalld zones and basic packet filtering are explicit RHCSA (EX200) objectives, and this lab drills exactly that scope.
Ready to run this lab yourself?
No setup, no image sourcing. Book a session or ask for a live demo.