Author: Asad Ijaz

NetworkUstad's lead networking architect with CCIE certification. Specializes in CCNA exam preparation and enterprise network design. Authored 2,800+ technical guides on Cisco systems, BGP routing, and network security protocols since 2018. Picture this: I'm not just someone who writes about tech; I'm a certified expert in the field. I proudly hold the titles of Cisco Certified Network Professional (CCNP) and Cisco Certified Network Associate (CCNA). So, when I talk about networking, I'm not just whistling in the dark; I know my stuff! My website is like a treasure trove of knowledge. You'll find a plethora of articles and tutorials covering a wide range of topics related to networking and cybersecurity. It's not just a website; it's a learning hub for anyone who's eager to dive into the world of bits, bytes, and secure connections. And here's a fun fact: I'm not a lone wolf in this journey. I'm a proud member and Editor of Team NetworkUstad. Together, we're on a mission to empower people with the knowledge they need to navigate the digital landscape safely and effectively. So, if you're ready to embark on a tech-savvy adventure, stick around with me, Asad Ijaz Khattak. We're going to unravel the mysteries of technology, one article at a time!"
Diagram illustrating the fundamentals of network switching and its components.
CCNA June 5, 2019

Switching Fundamentals – Everything to Know

An Ethernet switch is a Layer 2 device. Therefore, the switch uses MAC addresses for switching decisions. It is unaware of the protocol being carried in the data portion of the frame, such as an IPv4 packet. The Ethernet hub repeats bits out of all ports except the incoming port, but an Ethernet switch consults […]
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Image illustrating the Address Resolution Protocol (ARP) in network communication.
CCNA June 4, 2019

Address Resolution Protocol (ARP)

The source host uses Address Resolution Protocol (ARP) to determine the destination MAC address. Although the destination MAC address can be a unicast, broadcast, or multicast, the source MAC address must always be unicast. Every device with an IP address on a network also has an Ethernet MAC address. When a device sends an Ethernet […]
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Diagram illustrating unicast, multicast, and broadcast addresses in network communication.
CCNA June 4, 2019

Mastering Unicast, Multicast, and Broadcast Addresses in 2025

In Ethernet, Multicast, and Broadcast Addresses always describe a group of recipients. However, the unicast explains communication where data is sent from one point to another. Unicast Address A unicast address means a packet has been sent from a single source to a specific destination. All Ethernet and IP networks support unicast transmission. A unicast […]
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Diagram illustrating the structure and function of a MAC address
CCNA June 4, 2019

Understanding MAC Addresses: Structure, Importance, and How to Find Them in 2025

A media access control address, or a device’s MAC address, is a worldwide unique identifier assigned to a network interface controller. It is also known as “hardware address” or “physical address” and is very important for communication within network segments. Most IEEE 802 network technologies, including Ethernet, Wi-Fi, and Bluetooth, use a Media Access Control address for within-network […]
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Diagram illustrating the structure and fields of an Ethernet frame.
CCNA June 4, 2019

Ethernet Frame Structure: A Guide to IEEE 802.3 in 2025

In 2025, the Ethernet frame structure, defined by IEEE 802.3, is the backbone of wired and wireless networking, enabling reliable data transfer in everything from smart homes to data centers. This guide explores the components of an Ethernet frame, their roles, and their relevance in modern networks like 400GbE and IoT. Overview of Ethernet Frame […]
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Diagram illustrating the Data Link layer divided into LLC and MAC sublayers.
CCNA June 3, 2019

Understanding LLC and MAC Sublayers in the Data Link Layer (2025)

In 2025, the Data Link Layer is critical for reliable network communication, enabling devices to transfer data efficiently across wired and wireless networks. Its two sublayers—Logical Link Control (LLC) and Media Access Control (MAC)—play distinct roles in framing, addressing, and error control. This guide explores their functions, differences, and relevance in modern networking, from Ethernet […]
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Illustration of an Ethernet port with the text "Different Ethernet Standards" on a blue background.
CCNA June 3, 2019

Ethernet Standards: The Backbone of Modern Networking in 2025

In 2025, Ethernet standards remain the cornerstone of reliable, high-speed networking for homes, businesses, and data centers. From streaming 8K videos to powering smart cities, Ethernet’s balance of speed, affordability, and scalability makes it the go-to technology for wired networks. This guide explores Ethernet’s evolution, key standards, and how to choose the right one for […]
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Diagram illustrating framing in the data link layer, showing different types of frames used in network communication
CCNA June 2, 2019

Framing in Data Link Layer – Exclusive Explanation (Updated 2025)

Data-link layer framing is a critical process in networking, enabling reliable data transmission across diverse media. The data-link layer takes packets from the Network Layer and encapsulates them into frames, the fundamental data units for network communication. If the frame size becomes too large, the packet may be divided into smaller frames to ensure efficient […]
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Feature image for an article titled 'CARRIER SENSE MULTIPLE ACCESS (CSMA)' with a colorful patchwork border and the NetworkUstad logo in the bottom right corner.
CCNA June 2, 2019

Carrier Sense Multiple Access (CSMA): Explained for 2025

Carrier Sense Multiple Access (CSMA) is a network protocol that listens for a carrier signal before transmitting data, reducing collisions on shared transmission media like Ethernet and Wi-Fi networks. By checking the state of the medium before sending, CSMA ensures efficient data transmission in networks with multiple devices. As part of the Media Access Control […]
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