Networking

How to find the correct MTU and MRU of your link

Overview In the previous post, I talked about Network IP Fragmentation, what it is and why it’s needed (You are advised to read it before continuing). I also covered the so called PMTUD Black hole effect. Fixing a PMTUD Black hole is a multistep process, and it starts with finding the correct MTU/MRU of your link. Now as I’ve discussed, every path can have its own unique MTU/MRU value, but we are usually interested in the max value that is dictated by your ISP.

Understanding Network IP Fragmentation

In this post, I'm going to talk about what IP fragmentation is, how it works and why it's needed. And while learning that, we're going to touch on subjects like OSI Layers / PDU / MTU / MRU and PMTUD.

How to install LUKS encrypted Ubuntu 18.04.x Server and enable remote unlocking

Much has been changed since my last post about LUKS remote unlock workaround. This is the updated version on how to set things up properly.

How to Fully Uninstall Kaspersky's NDIS Filter

I like Kaspersky anti-virus, and I use it regularly… (Not on my own PC mind you, but on the clients) While I do believe they provide the best anti-virus in the market, I am not a fan of most of their other products. That goes for the Firewall, Safe Browsing, SSL Hijacking, and of course their newest addition, Secure Connection…

Remote unlocking of LUKS-encrypted root in Ubuntu/Debian

Not so long ago, remote unlocking of a LUKS-encrypted root partition was difficult to setup. While essential for headless servers, all required steps needed to be done manually and compatibility was a concern. Luckily, it is much simpler to do so in recent versions of Ubuntu/Debian. Unlocking an encrypted root remotely *should* be as simple as installing a single package... We'll see about that in a moment.

OpenVPN TAP adapter MTU in Windows

Recently I was in need of setting up some windows clients to connect to my OpenVPN server. This server running on Linux, uses a specific MTU value (let’s say 1400) to ensure maximum compatibility with different clients over different links.

Optimizing OpenVPN Throughput

In the previous post, I talked about OpenVPN TCP and UDP tunnels and why you should not be using TCP. In this post, I’m going to talk about optimizing the said tunnels to get the most out of them.

OpenVPN - TCP or UDP tunneling?

Spoiler alert: You most likely would want to use UDP tunneling! An OpenVPN tunnel runs over IP and can encapsulates VPN traffic into either a UDP or a TCP connection. To understand the pros and cons of each, we first need to have an understanding of them both.