COURSE

Configure Linux Firewall ACL Rules

Course

This Configure Linux Firewall ACL Rules IT Pro Challenge helps learners understand the basic concepts of ufw (uncomplicated firewall) behind using ping to test the firewall and how to manipulate firewall rules to allow and deny network traffic.

Full access included with 
Insider Pro
 and 
Teams

0

H

45

M
Time

beginner

i
Designed for learners who have no prior work experience in IT or Cybersecurity, but are interested in starting a career in this exciting field.
Designed for learners with prior cybersecurity work experience who are interested in advancing their career or expanding their skillset.
Designed for learners with a solid grasp of foundational IT and cybersecurity concepts who are interested in pursuing an entry-level security role.
Experience Level

i

Earn qualifying credits for certification renewal with completion certificates provided for submission.
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About this course

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Course Outline

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Course Description

After taking this Configure Linux Firewall ACL Rules IT Pro Challenge lab, learners will understand how to view, configure, and modify firewall rules to block and allow SSH traffic. They will learn how to verify the changes that they make, how to use sudo commands, and why some companies choose to block SSH traffic.

Anyone pursuing a career as a systems or network administrator needs to have knowledge of firewall rules and how order matters.

Overview

The objective of this virtual lab is to help the learner understand how to control inbound and outbound network traffic to a specific Linux server by enabling the firewall, configuring the firewall rules to both allow and deny network traffic, and then re-ordering a firewall rule.

The learner will become comfortable using various commands (ping, ifconfig, sudo) to manipulate firewalls and rules and view the results of any changes that they make to the firewall rules.

They will also gain an understanding of ICMP and why some companies choose to block echo requests to mitigate damage that could be caused by a hacker or attack.

Turn on the firewall

First, you’re going to learn how to obtain the IP address of a machine by using the ifconfig command. You will then ping that IP address and view the results.

Then you’re going to use the sudo ufw status command to view the firewall status, and the sudo ufw enable command to enable the firewall. You will verify that the running firewall is enabled by running the sudo ufw status verbose command.

Uncomplicated Firewall (UFW) is an easy to use (uncomplicated) command line program for managing firewalls. The sudo command allows you to execute a command as another user.

Block ICMP echo requests

ICMP is a protocol commonly used on network devices like routers to send error messages as well as success/fail messages from communication with another IP address. Many companies choose to block ICMP echo requests to avoid an issue called “ping flood,” whereby an attacker can bombard the system with so many ping requests that it results in a denial of service error.

In this part of the virtual lab, you’re going to block ICMP echo requests by editing the before rules file and commenting out the line that allows ping requests. You will verify your work by trying to ping the server for which you just blocked echo requests.

Allow SSH traffic through the firewall

Secure Shell (SSH) is a secure network protocol that is used to secure network traffic on an unsecured network.

To allow SSH traffic, you’re going to configure a firewall rule on the first Linux server. You will test your work by logging into the second Linux server to create an SSH connection to the first Linux server.

Block all traffic from Linux2

Finally, you will learn how to block all traffic from a Linux server, as well as view the numbered firewall rules and re-order those rules. You will verify that you blocked all traffic by trying to create an SSH connection to the server and seeing the connection time out.

Summary Conclusion

By taking this virtual lab, you will learn how to enable the Linux UFW, configure various firewall rules to both allow and deny network traffic, and configure and re-order firewall rules.

Through this process, you will learn about UFW and how to use various sudo command line operations to manipulate and view firewall rules.

Train Your Team

Cybrary’s expert-led cybersecurity courses help your team remediate skill gaps and get up-to-date on certifications. Utilize Cybrary to stay ahead of emerging threats and provide team members with clarity on how to learn, grow, and advance their careers within your organization.

Included in a Path

Instructors

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Learn

Learn core concepts and get hands-on with key skills.

Practice

Exercise your problem-solving and creative thinking skills with security-centric puzzles

Prove

Assess your knowledge and skills to identify areas for improvement and measure your growth

Get Hands-on Learning

Put your skills to the test in virtual labs, challenges, and simulated environments.

Measure Your Progress

Track your skills development from lesson to lesson using the Cybrary Skills Tracker.

Connect with the Community

Connect with peers and mentors through our supportive community of cybersecurity professionals.

Success from Our Learners

"Cybrary really helped me get up to speed and acquire a baseline level of technical knowledge. It offers a far more comprehensive approach than just learning from a book. It actually shows you how to apply cybersecurity processes in a hands-on way"

Don Gates

Principal Systems Engineer/SAIC

"Cybrary’s SOC Analyst career path was the difference maker, and was instrumental in me landing my new job. I was able to show the employer that I had the right knowledge and the hands-on skills to execute the role."

Cory

Cybersecurity analyst/

"I was able to earn my CISSP certification within 60 days of signing up for Cybrary Insider Pro and got hired as a Security Analyst conducting security assessments and penetration testing within 120 days. This certainly wouldn’t have been possible without the support of the Cybrary mentor community."

Mike

Security Engineer and Pentester/

"Cybrary really helped me get up to speed and acquire a baseline level of technical knowledge. It offers a far more comprehensive approach than just learning from a book. It actually shows you how to apply cybersecurity processes in a hands-on way"

Don Gates

Principal Systems Engineer/SAIC

"Cybrary’s SOC Analyst career path was the difference maker, and was instrumental in me landing my new job. I was able to show the employer that I had the right knowledge and the hands-on skills to execute the role."

Cory

Cybersecurity analyst/

"I was able to earn my CISSP certification within 60 days of signing up for Cybrary Insider Pro and got hired as a Security Analyst conducting security assessments and penetration testing within 120 days. This certainly wouldn’t have been possible without the support of the Cybrary mentor community."

Mike

Security Engineer and Pentester/

"Becoming a Cybrary Insider Pro was a total game changer. Cybrary was instrumental in helping me break into cybersecurity, despite having no prior IT experience or security-related degree. Their career paths gave me clear direction, the instructors had real-world experience, and the virtual labs let me gain hands-on skills I could confidently put on my resume and speak to in interviews."

Cassandra

Information Security Analyst/Cisco Systems

"I was able to earn both my Security+ and CySA+ in two months. I give all the credit to Cybrary. I’m also proud to announce I recently accepted a job as a Cyber Systems Engineer at BDO... I always try to debunk the idea that you can't get a job without experience or a degree."

Casey

Cyber Systems Engineer/BDO

"Cybrary has helped me improve my hands-on skills and pass my toughest certification exams, enabling me to achieve 13 advanced certifications and successfully launch my own business. I love the practice tests for certification exams, especially, and appreciate the wide-ranging training options that let me find the best fit for my goals"

Angel

Founder,/ IntellChromatics.

Configure Linux Firewall ACL Rules

This Configure Linux Firewall ACL Rules IT Pro Challenge helps learners understand the basic concepts of ufw (uncomplicated firewall) behind using ping to test the firewall and how to manipulate firewall rules to allow and deny network traffic.

0
45
M
Time
beginner
difficulty
ceu/cpe

Course Content

Course Description

After taking this Configure Linux Firewall ACL Rules IT Pro Challenge lab, learners will understand how to view, configure, and modify firewall rules to block and allow SSH traffic. They will learn how to verify the changes that they make, how to use sudo commands, and why some companies choose to block SSH traffic.

Anyone pursuing a career as a systems or network administrator needs to have knowledge of firewall rules and how order matters.

Overview

The objective of this virtual lab is to help the learner understand how to control inbound and outbound network traffic to a specific Linux server by enabling the firewall, configuring the firewall rules to both allow and deny network traffic, and then re-ordering a firewall rule.

The learner will become comfortable using various commands (ping, ifconfig, sudo) to manipulate firewalls and rules and view the results of any changes that they make to the firewall rules.

They will also gain an understanding of ICMP and why some companies choose to block echo requests to mitigate damage that could be caused by a hacker or attack.

Turn on the firewall

First, you’re going to learn how to obtain the IP address of a machine by using the ifconfig command. You will then ping that IP address and view the results.

Then you’re going to use the sudo ufw status command to view the firewall status, and the sudo ufw enable command to enable the firewall. You will verify that the running firewall is enabled by running the sudo ufw status verbose command.

Uncomplicated Firewall (UFW) is an easy to use (uncomplicated) command line program for managing firewalls. The sudo command allows you to execute a command as another user.

Block ICMP echo requests

ICMP is a protocol commonly used on network devices like routers to send error messages as well as success/fail messages from communication with another IP address. Many companies choose to block ICMP echo requests to avoid an issue called “ping flood,” whereby an attacker can bombard the system with so many ping requests that it results in a denial of service error.

In this part of the virtual lab, you’re going to block ICMP echo requests by editing the before rules file and commenting out the line that allows ping requests. You will verify your work by trying to ping the server for which you just blocked echo requests.

Allow SSH traffic through the firewall

Secure Shell (SSH) is a secure network protocol that is used to secure network traffic on an unsecured network.

To allow SSH traffic, you’re going to configure a firewall rule on the first Linux server. You will test your work by logging into the second Linux server to create an SSH connection to the first Linux server.

Block all traffic from Linux2

Finally, you will learn how to block all traffic from a Linux server, as well as view the numbered firewall rules and re-order those rules. You will verify that you blocked all traffic by trying to create an SSH connection to the server and seeing the connection time out.

Summary Conclusion

By taking this virtual lab, you will learn how to enable the Linux UFW, configure various firewall rules to both allow and deny network traffic, and configure and re-order firewall rules.

Through this process, you will learn about UFW and how to use various sudo command line operations to manipulate and view firewall rules.

This course is part of a Career Path:
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Certificate of Completion

Complete this entire course to earn a Configure Linux Firewall ACL Rules Certificate of Completion