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Enabling Kernel Modules and Modifying Parameters

In this hands-on lab, you will view the current command-line kernel parameters using `/proc/cmdline` or `dmesg`. With the current configuration noted, next check for a couple of runtime kernel parameters using `sysctl`, followed by using `lsmod` to check the status of specific kernel modules. Based on the status of each, you will used `modprobe` to enable/disable kernel modules and make kernel parameter changes by using `sysctl` and creating configuration files in the appropriate directory locations. The final task will be to reboot the system and confirm the changes. *This course is not approved or sponsored by Red Hat.*

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Path Info

Level

Advanced

Duration

30m

Published

Jun 30, 2021

Challenge

Review the Current Kernel Command Line Parameters
- Review the appropriate file or execute the proper command to view the current kernel command line parameters.
- Confirm the crashkernel option is set to auto.
Challenge

Confirm the Status of Specific Kernel Runtime Parameters
- Determine if the kernel runtime parameters net.ipv4.ip_forward and net.ipv6.conf.default.forwarding are enabled.
- If either parameter is disabled, immediately enable it using the appropriate command.
- If either parameter is disabled, use vim to create a configuration file called /etc/sysctl.d/10-network.conf.
- Add any disabled kernel parameters from the previous step to the 10-network.conf file and save the changes.
Challenge

Determine the Status of Specific Kernel Modules
- Using the appropriate command, determine the status of the bluetooth, bridge, and cdrom kernel modules. The status should be set as the following:
  - bluetooth = inactive
  - bridge = active
  - cdrom = active
- If any of the of the modules are incorrectly configured, make the following changes
  - If bluetooth is enabled, use the appropriate process to ensure the module will not start after a reboot and cannot be manually started.
  - If bridge is disabled, use the appropriate process to enable the command and ensure it will start after a reboot.
  - If cdrom is disabled, use the appropriate process to enable the command and ensure it will start after a reboot.
Challenge

Validate System Changes
- Reboot the server to ensure changes are applied.
- Log back in after the reboot has completed.
- Confirm the following configuration changes:
  - Kernel runtime parameters
    
    Confirm net.ipv4.ip_forward is enabled.
    
    Confirm net.ipv6.conf.default.forwarding is enabled.
  - Kernel modules
    
    Confirm bluetooth is not active. Check the exclusion list and attempt to manually enable the module.
    
    Confirm bridge is active.
    
    Confirm cdrom is active

Author

A Cloud Guru

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.