A brief, high-level introduction to Linux networking architecture. Explains how the Linux kernel manipulates network traffic using a top-down approach and basic framework to route
Have you ever wondered why Linux network management is so confusing? You need only make a cursory review of the history of Linux networking tools to understand how it got this way.
Two systems built-in to Ubuntu manage network routing: route (a legacy system) and ip route. Both use the same underlying code, yet report networking context a
Having explained the process behind gateway routes in the previous article, what is a split
Hopefully, you have already read and/or understand these concepts:
Routers manage routes. Some routers act as gateways. A gateway is a forwarding router that forms a bridge between local and remote networks. A gateway is required when sending a packet
A critical component of managing routes is understanding the role netmasks play in managing routing traffic. More commonly known as the netmask, the sub-network mask or
What is a Netmask (or Genmask)? And why is understanding it so important when it comes to network routing?
Thinking of creating split routes or split gateways? This article is a basic introduction, but it is a hands-on tutorial and will walk you through the building blocks of
Here are a few helpful tips related to rule and route testing.
If you make changes to ip rules, ip routes, or iptables and wish to utilize them prior to
One of the challenges of iptables, routes, and rules (iprules) is making changes to them permanent. Any changes you make on-the-fly only last until the next system restart.
Chart of the most commonly used iptables rule syntax, demonstrating command syntax along with the tables and chains where each command may be utilized. The table scrolls
Routing tables inform the Linux kernel where to find destinations on a network. They describe information such as which network interface to send
It's much easier for most people to reference charts of netmask/genmask/CIDR values vs. trying to remember them (though some common masks such as 0 and 255 are easy
Here are some brief concepts to keep in mind when adding new routes and routing tables.
High level concepts to keep in mind when adding new
There are a large number of filters you may apply to your server's network rules via the iptables command. Some of these are found in extensions to iptables.
The following
Did you know in the United States, the NSA (National Security Agency) routinely monitors all internet traffic coming in or out of the United States?1 Were you aware
This article explores why "Best" lists of VPN providers are not useful.
There are many, many VPN service providers on the market. Hundreds. No joke. VPNs are "in."
I.T. networking is a HUGE topic, and I am by no means going to cover every concept, tool, and scenario. What you will find here is a series of mini-guides designed to help you gain a basic
This category primarily covers:
Virtually any file system you apply to a Linux operating system (such as Ubuntu) will have ACL capabilities. ACL is an acronym for "Access Control List." In simple terms, it means the file system
Several processes control the flow of data through a Samba-managed network connection. Ironically, the most important of them has nothing to do with networking.
Andreasson, Oskar. Iptables Tutorial 1.2.1. Chapter 6: Traversing of tables and chains. https://www.frozentux.net/iptables-tutorial/chunkyhtml/c962.html.
Andreasson, Oskar. 2006.
We will begin the detailed discussion of the first component of the Routing Policy DataBase (RPDB) triad: routes (the other two components are ip rules and ip
A traditional router stores network route information in routing tables. A routing table is a map of a network. Linux uses a policy based routing system, aptly called a
Now that you have a basic understanding of Linux network routing, it's time to delve into some interesting things you can do with this information.
Here are
This section describes the use of alternative tools to the iproute2 suite for viewing the status of a network. They may be old, but route and netstat can still be useful
Contemplating signing up for a Virtual Private Network (VPN)? Why? The truth is most people don't need them, most of the time. Here's how to determine if it truly makes sense for you.
This is a list of sources I found useful while writing my comprehensive guides on VPNs for Small Business Owners, Home Office Workers, and Split VPNs
The process of selecting a VPN provider should not be taken lightly. The more one is concerned with privacy or anonymity, the fewer good choices there are. VPNs are a crucial component of a
VPN is an abbreviation for Virtual Private Network.
A VPN is a secure, virtual
If you could sum up the purpose of a Virtual Private Network (VPN) in one word, what would it be? My choice: Integrity.
Of course, I'm talking about data integrity. But, what
Which VPN service providers are worthy of your time and which should you avoid like The Plague?
There are so many VPN providers these days (over 300), and so many "reviewers," it has
A split gateway divides outgoing network traffic between two or more gateways. This is most common with traffic traveling from a private network out to the
Although I'm a big proponent of VPNs, the industry has become littered with mis-information and outright shams, creating a mixed environment when it comes to advertised claims of privacy
How does someone who is not a VPN subject-matter expert choose a VPN provider? Often by reading reviews of various service providers. Yet, how can one tell the difference between a real review
This article explains common network cryptographic concepts in plain-English.
WireGuard is the "new kid on the block" in the world of VPNs.
Protocol adoption in the VPN world is a very slow process. Yet a relatively recent upstart is garnering a lot of attention:
Tunnels in the IT networking world refers to a communications channel connecting two (2) networks or devices when those devices reside on different local networks or sub-nets. A tunnel
Primarily covers iptables, ipchains, and ip rules. It also touches on ufw (Uncomplicated FireWall), and nftables ("NetFilter Tables"), the successor
This category contains articles about Virtual Private Networks (VPNs), such as what they are, why you may or may not need or want one, how they function, and how to pick the best VPN service
Dedicated DNS. Dynamic DNS. Smart DNS. What the heck are these things???
Many consumers get confused between these very distinct services. It's not their fault. I blame the marketing
This article is about digital privacy and specifically, safeguarding your privacy online through the use of Virtual Private Networks and Domain Name System masking
This article is Part 1 in a 3-part series on how Virtual Private Networks (VPNs) work. Part 1 delves into the nuances of VPNs at a high-level, scratching the surface on the inner workings of VPN
Table comparing the complete list of all OpenVPN versions. See below for pertinent notes.
The entertainment industry has developed numerous techniques to restrict end users' ability to access digital content based on geographic location. End users trying to dodge these geographic
This article examines the relationship between OpenVPN and OpenSSL, why the former depends on the latter, and why it's important to remain cognizant of software version numbers
OpenVPN is an open source Virtual Private Network (VPN) software solution that rivals similar commercially available products. It allows you to use PKI (Public Key Infrastructure) and SSL/TLS
Thinking of combining a Virtual Private Network (VPN) service with a Smart DNS service? If you'll be running both services on the same device, before you leap forward with your plans it's wise to
This article is Part 3 in a series of three (3) articles about how Virtual Private Networks (VPNs) work. While I get into some technical details, the intent is to scratch the surface just enough
This document is a comprehensive, high-level overview of what IPsec is and how it works.
IPsec is a flexible network security framework that may be applied to a number of different use
IKEv2 is a security protocol that facilitates cryptographic symmetric key exchanges between endpoints.
This article is Part 2 in a series of articles about how Virtual Private Networks (VPNs) work. Part 1 of the series,
A newly discovered security vulnerability exists in most modern operating systems which allows a malicious actor to hijack an active TCP-based VPN connection, without the need to break its
