The Linux kernel is flexible, and you can even modify the way it works on the fly by dynamically changing some of its parameters, thanks to the sysctl command.

Today most kernels work out of the box with most hardware. But there are times when you could squeeze out a bit more performance or even lighten your kernel on the fly. You can do that with the sysctl command.

The Linux kernel is flexible, and you can even modify the way it works on the fly by dynamically changing some of its parameters using sysctl command.

The Linux kernel and the distributions that package it typically provide very conservative defaults to certain network settings that affect networking parameters. These settings can be tuned via the /proc filesystem or using the sysctl program. The latter is often better, as it reads the contents of /etc/sysctl.conf, which allows you to keep settings across reboots.

It is indeed a powerful tool, and if you know how to use it, you can tweak the kernel, and the changes are applied immediately.

net.ip.portrange.* The net.inet.ip.portrange.* sysctl variables control the port number ranges automatically bound to TCP and UDP sockets.

This happens lot of times. I login as a normal user and start to edit httpd.conf or lighttpd.conf or named.conf in vim / vi text editor. However, I'm not able to save changes due to permission issue (all config files are owned by root). How do I save file without creating a temporary file (/tmp/httpd.conf) and then move the same (mv /tmp/httpd.conf /etc/httpd) as root using vim / vi itself?

In recent times, the xorg.conf (or formerly, XFree86.conf) file once used for configuring all static X-related server options has been shrinking in size. Thanks to more reliable EDID (Extended Display Identification Data) on LCD panels, it's generally no longer needed to manually specify mode-lines within this X.Org configuration file.

* Part 1: Introduction to Snort intrusion detection and prevention
* Part 2: Hardware and network setup requirements
* Part 3: Installation prerequisites
* Part 4: Compiling and configuration with MySQL
* Part 5: Configuring Snort and setting up rules
* Part 6: Editing the snort.conf file