Linux+ Troubleshooting: Troubleshoot Networks
In this lab, you will gain hands-on experience in checking the network details of the server, and testing its connectivity with other servers. You will also learn how to troubleshoot issues related to a malfunctioning NIC (Network Interface Card) or port, which can cause packet drops and impact network performance. Furthermore, you will acquire practical knowledge of various commands to check DNS name resolution. In addition, you will also configure a firewall and scan ports on remote servers using the nmap command.
Terms and conditions apply.
Challenge
Get Started in the Lab Environment
Here are the initial instructions and explanation of the lab environment. Read this while your environment is busy creating itself from nothing. Yes, this violates physics; we know. How fun!
Challenge
Check Network Connectivity
To start the lab, you will gain hands-on experience in understanding how to check the network details of a server and test the connectivity between servers using the ping command.
Challenge
View Dropped Packets on the NIC
Now, you will learn how to check the statistics of your NIC (Network Interface Card) and view raw data. By doing so, you can troubleshoot any issues that may arise from a malfunctioning NIC or port. These issues can lead to packet drops, which in turn can cause packet retransmissions, and have a negative impact on network performance.
Challenge
Check Name Resolution
The goal of this challenge is to comprehend the purpose and functionality of the /etc/nsswitch.conf file. Additionally, you will examine how the system utilizes the nss configuration file to query the server. Moreover, you will acquire practical knowledge of various commands such as resolvectl, dig, and getent. These commands are employed for querying and resolving the Domain Name System (DNS).
Challenge
Test Network Access
You will test network access by pinging the default gateway, and will troubleshoot subnet-related issues. You will also learn various shortened addresses to use with ping.
Challenge
Test and Configure a Firewall
In order to complete this lab, you will be taught how to configure the server's firewall. Additionally, you will utilize the nmap command to scan the ports on a remote server. Your objective is to permit a specific port to pass through the firewall from one server, and subsequently confirm its accessibility from another server.
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.
Recommended prerequisites
- Basic knowledge of Linux commands
- Knowledge of how to use vim
- Familiarity with networking concepts, namely those covered in the video course CompTIA Linux+: Troubleshooting