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IP in Practice: IPv4 Address Structure & Classes

There are two main types of IP addresses: IPv4 and IPv6. Many of us are familiar with the first option. The first post in this series included an interactive section where you could test IP addresses. Stay tuned for IPv6. The numbers may seem random, but did you know your IP address matters? It matters for our privacy and could also matter to external actors if they can gain access to our systems. I, however, am talking about what it could reveal. Is your IP address private or public? How much does that affect the number of IP addresses that can be on a network? How are IP addresses organized into classes? In this post, I'll focus on answering each of these questions. Structure of an IPv4 Address Follows a dotted-decimal notation Has four octets Each octet has a value between 0 and 255, made up of 8 bits Has a total length of 32 bits in binary form What are I...

IP in Practice: IP Addressing Basics

Whenever you order at a fast-food restaurant, the cashier may give you a number or ask for the name on your order. When your order is ready, they will call your number or name so the correct person receives it. Similarly, devices on a network are assigned a unique number so information reaches its intended destination. This number is called an IP address. . . . Check Full IP IP Addresses are Unique Identifiers Every device on a network has an IP address that allows it to communicate with other devices. These addresses are unique within a network to ensure data reaches its intended destination. Imagine if two people had the same order number—there would be confusion about who ordered what. Similarly, without these identifiers, devices would not know where to send or receive data. Purposes of IP Addresses IP addresses serve several purposes, including: Routing: IP addresses operate at layer 3 of the TCP/IP or OSI model, also kno...

New Series: IP in Practice

I have done a few posts on subnetting and the inner workings of DHCP. I wanted to do a post on IPv6 and a hands-on demo on implementing DHCP on actual networking equipment. However, I missed a few parts that I would like to cover that would particularly help in understanding how IP works and why it is needed. Unlike the previous series, this will be a direct approach to a certain protocol: Internet Protocol (IP). I recently started my first series, covering important ports, protocols, and acronyms used in the networking field. However, I realized not only is it difficult to address the ones to mention, but for some letters it's hard to find. The intended structure was to have several per letter not just one. The idea seemed fun and engaging, however, doing over 20 posts alphabetically on acronyms, ports, and protocols lacks order and deviates from the direct approach I want this blog to have. For that reason, I am putting it on hold indefinitely. It was fun at first, but it was not...

Why I Chose Networking: My 5 Whys

Image created by ChatGPT I recently rewatched an episode of The Art of Network Engineering where hosts Andy Lapteff  and William Collins  interviewed Muna Chimso about his dual experience in networking and programming. In their conversation, Andy asked a thought-provoking question:  "Why doesn't anybody want to go into networking?" It's a valid question. I have met people who struggle with networking, but that's not the point. Many are drawn to other fields: cybersecurity, programming, AI & machine learning, the cloud ... the list goes on. I reflected on the question for myself. What drew me to networking? Here are my 5 answers. Maybe you can relate. 1. Networking is everywhere Everything relies on a network. Think about it: our smartphones, operating systems, and driverless cars all rely on a network for communication. Because it is so pervasive, understanding networking can make troubleshooting quicker and easier. Improving your home network can be exciti...

Understanding OSI and TCP/IP Models

Visual breakdown of the OSI Model's 7 layers Whether you are new to IT or a seasoned admin, chances are you have heard of the OSI or the TCP/IP model. These frameworks help us understand how data flows across our networks — from online shopping to high-speed data transfers. However, many job postings require knowledge of TCP/IP but not OSI. Why is that? Is one favored over the other? Let's take a look at both. What is the OSI Model?  Introduced in the 1980s, the Open System Interconnect — OSI — breaks down network communication into seven layers, each with a specific function. Layer Functions 7. Application User and device interaction for network services (web browsing, email, file transfer) 6. Presentation Formats data for applications, ensures readable and secure data 5. Session Establishes, maintains, and ends connections between devices. For example: Online shop...

DHCP Security: Shrinking the Attack Surface

A reservation means nothing if you get the wrong size for your guests, or a party crasher, intended or not, is there first. Similarly, if DHCP is not secure, your device runs the risk of not getting the right network configuration—or any at all. What threats does DHCP face, and how can we protect both devices and the server from such attacks? Let's secure those answers. For a refresher on DHCP, check out this post . DHCP Attacks Rogue DHCP Server On picnic day, you go to the park office to claim your pavilion, but another staff member—different from the one you arranged the event with—has no note of your reservation and gives you another pavilion. What does that mean for your guests? They already have the original location. Things just got complicated. Similarly, a rogue DHCP server is an unauthorized or misconfigured device that disrupts the operations of an authorized server within a network. This can result from manually assigning conflicting IP address ranges or some...

How Reserving a Pavilion Explains DHCP

It’s party time! You decide to throw a party at a park with a bunch of pavilions. But you can’t just walk up and claim a pavilion. Instead, you have to go through the park’s reservation service. You tell them the date and time of your event, and they check their list to see what’s available. Great news! A pavilion is open, and they assign it to you for a set time. The day arrives, and as planned, you host your party until it’s time to leave. What a great gathering! This is a lot like how DHCP works in a network. When a device — like your phone or laptop — joins a network, it can’t just start communicating. It needs an IP address first, just like you needed a reserved pavilion. Then, what is the "reservation" process of getting an IP address? Let's take a dive into the automated world of DHCP. What is DHCP? The Dynamic Host Configuration Protocol simplifies network provisioning by automatically assigning important network parameters. These include: IP addresses : Just as ...

Subnets: Key to Network Organization

Whether it is a to-do list or a big project, organization is key. We have busy lives. The task in itself can have several parts or may require some sort of collaboration with a partner or a team. A project may call to meet deadlines, which means keeping up with those crucial dates and having a system of order. Similarly, our networks are busy, transferring a great deal of data across links and nodes. The amount of traffic generated can lead to bottlenecks, packet loss, and delays. A network’s design can vary in complexity, depending on the environment or needs of a customer. Just as we find a manageable way to handle heavy workloads, our networks have a way of efficiently handling network traffic by creating "mini-networks" within our network. This process is called subnetting.   Why We Subnet To reduce congestion. Just as traffic in cities cause slowdowns and delays, too much traffic can lead to bottlenecks, packet loss, and delays. Subnetting breaks the netwo...

A Nesting Doll of Networks: Types of Networks

  PAN, WAN, MAN, LAN, CAN - what is up with all these rhyming words? As fun it us to relive kindergarten, these are acronyms for the types of networks that exist today. Think of them as digital nesting dolls: PANs can be found in LANs, LANs make up our WANs, and there is more in between. Let's take a closer look at these networking nesting dolls. Personal Area Networks (PANs) Have you ever grown frustrated at how your Bluetooth headphones seem to take forever to pair to your phone? Do you use a wired mouse or a wireless mouse with your desktop? Do you "tap to pay"? These are examples of personal area networks.  A personal area network connects devices close in range, from a few centimeters to a few meters. These types of networks can be wired or wireless.  A wired PAN may be a computer connected to a printer by a USB cable or Ethernet cable.  A wireless PAN may use communication methods, such as Bluetooth, infrared, or radio waves. Think of your wireless Bluetooth ea...

Make a Connection: What Is a Network?

The term "network" has been defined countless times. If there is anything I have learned about something being repeated many times, it means it is important. With networks, that is no different. I defined networking previously and briefly - a collection of devices that receive and transmit data amongst each other. Yet, it truly does not do it justice. I just finished my first co-op iteration at Motorola Solutions. Entering this new opportunity for me was more than just a foot in the door in the field of networking. I got to see critical infrastructure that transmitted and received signals relayed from first responders' and public sector communications. Long story short, I got to see the inner workings of a network, especially how different media and architecture converges to keep communications clear and functioning. Humanizing Networks   The world's networks, big and small, have been compared to:  Extensive highways that carries information across "tolls", ...