Linux Kernel
Tasks
- Install a new version of the kernel.
- Enable packet forwarding.
Solution
1. Install a new kernel version
Before installing a new kernel, it's useful to check which versions are available in your distribution's repositories.
sudo yum list available kernel
Choose the kernel version you want to install based on the output of the previous command. Replace <kernel-version> with the actual version number you want to install.
sudo yum install kernel-<kernel-version>
For example, to install kernel version 5.15.0, you would run:
sudo yum install kernel-5.15.0
After installing the new kernel, update the bootloader configuration to ensure it is included in the boot menu.
sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Or, for UEFI-based systems:
sudo grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
To start using the new kernel, reboot your system:
sudo reboot
After rebooting, check that the new kernel version is running:
uname -r
This command will display the currently running kernel version.
2. Enable packet forwarding
Packet forwarding allows a Linux system to forward network packets from one network interface to another. Here’s how to enable it:
Temporary enablement (until next reboot):
sudo sysctl -w net.ipv4.ip_forward=1
To make this change persistent across reboots, edit /etc/sysctl.conf:
sudo nano /etc/sysctl.conf
Uncomment or add the following line to enable packet forwarding:
net.ipv4.ip_forward = 1
Save and exit the editor (Ctrl+X, then Y and Enter). Apply the changes:
sudo sysctl -p
This command reloads the sysctl settings from /etc/sysctl.conf and applies them.