Permitting and Blocking Traffic with the Firewall

30 minutes
  • 3 Learning Objectives

About this Hands-on Lab

In this hands-on lab, you will need to configure `Server1` ( so that it only permits HTTP connections (port 80) from `Client1` (

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Verify that a firewall is running.

You should already have iptables started and running. You can verify this with:

# systemctl status iptables

Verify that the host listening on port 80.

You’ll want to verify that the host has a service listening on port 80. You can do so using the following command:

# ss -lntp | grep :80

You should see that port 80 is listening for the httpd process.

Verify that port 80 is blocked, and add a rule to permit traffic coming from

From Client1 (, try to curl

[cloud_user@ip-10-0-1-11 ~]$ curl

You’ll need to add a rule to permit the traffic:

iptables -I INPUT -p tcp -s --dport 80 -j ACCEPT

Test from Client1 again, and also with Client2. If Client1 is successful and Client2 isn’t, save your existing chain with:

[root@ip-10-0-1-10 ~]# service iptables save

Additional Resources

Your organization has recently deployed a host to provide API endpoints for internal use, and wants to make this web traffic only available to a single client host on the network.

You must configure Server1 ( to only permit web traffic for Client1 ( Client2 ( is available for testing and confirmation.

What are Hands-on Labs

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.

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