NodeConnect

Do you speak another language? Personally, I love learning new languages, but one of the hardest parts is translation. When it comes to networking, it is something similar. Devices within our home and office networks do not directly go to the internet. There needs to be a "translator". What does this have to do with public and private IPv4 addresses? In this post, we will explore: IPv4 Addresses Private Ranges  The difference and teamwork between NAT and PAT Helpful troubleshooting commands such as ipconfig or ping A demo that puts it altogether.  (Link to topology here .) By the end of this post, you will see how public and private IP addresses work together in action.  IPv4 Address Private Ranges RFC1918 Private IP Address Ranges Class IANA Blocks Range Total Addresses A 10.0.0.0/8 10.0.0.0 - 10.255.255.255 16.7 million (16,777,216) ...

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...

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...

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...

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...

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...

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 ...

When I was first introduced to subnetting, it was difficult to understand the math and the process behind it. I watched videos but it did not click. I focused more on how to calculate it than on the reasoning behind it. Why do we subnet? I remember seeing forward slashes followed by numbers, classes, letters, network and broadcast addresses - important terms that was overshadowed by just trying to grasp why certain numbers were used.  Years later, I hear the word "subnetting" in one of my courses, and it reminded me of my struggles. Yet, I was excited. It was a time for redemption. Example after example, I started to get them right but also got to understand how to create a subnet with sufficient space for devices. Because of this, I have grown to love subnetting.  For me, it took time - a break that lasted about two years followed by a curriculum that focused on the topic for a few weeks. If you find yourself struggling with subnetting, do not worry. It takes time. If someth...

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...