Linux

What is QEMU?

QEMU (Quick Emulator) is a multifunctional open-source project that acts both as an emulator and a virtualizer, making it a unique tool in the virtualization world. Unlike other hypervisors, QEMU not only runs virtual machines but can also emulate a processor and other hardware components. This dual nature allows it to run operating systems and applications designed for one architecture on a machine with another (for example, running an ARM system on an x86 server).

What is KVM?

KVM (Kernel-based Virtual Machine) is a virtualization technology built directly into the Linux kernel. KVM transforms the Linux kernel into a Type 1 hypervisor (bare-metal), allowing multiple virtual machines to run while leveraging hardware virtualization features of the CPU (Intel VT-x and AMD-V). KVM serves as a core component for many modern cloud platforms, including OpenStack and Red Hat OpenShift.

As part of Linux, KVM is a fully open-source solution, giving developers and system administrators enormous freedom and control over their infrastructure with zero licensing fees.

In the world of Linux and networking technologies, there are many subtle but critically important kernel settings. One such setting is rp_filter. This parameter, often overlooked, plays a key role in network security and correct packet routing. Let’s explore what it is, how it works, and why understanding it is essential for every system administrator.

What is rp_filter?

rp_filter stands for Reverse Path Filtering. It’s a Linux kernel mechanism that checks incoming network packets to verify whether they arrived on the interface through which a reply to the sender’s IP address would be routed.

There’s often a need to host a website, be it a personal blog, a test project, or a small service, directly on a home computer. This is convenient, economical, and provides full control. However, many face the problem of not having a “white” (public) IP address from their internet provider, making direct external access virtually impossible. And even if they do, it’s often dynamic, requiring constant updates via DDNS.

Don’t worry! Today, we’ll dive into the world of network technologies and show you how to overcome this limitation and publish your website online using a powerful and free tool from Cloudflare – Cloudflare Tunnel (formerly known as Argo Tunnel). You won’t need a white IP, port forwarding on your router, or other complex configurations!