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 inter-VLAN routing using Switch Virtual Interface (SVI) on a Layer 3 switch connecting VLAN 100 (192.168.100.0/24) and VLAN 200 (192.168.200.0/24) with sample PCs.
CCNA August 25, 2019

What is Switch Virtual Interface (SVI) – Everything to Know

Switch Virtual Interfaces (SVIs) are a cornerstone of modern enterprise networking, enabling efficient inter-VLAN routing on multilayer switches. This guide, designed for CCNA and CCNP students, explores the evolution of Layer 2 and Layer 3 switching, SVI configuration, verification, troubleshooting, and real-world applications. Whether you’re preparing for certification exams or deploying networks, this article provides...
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Schematic diagram of Layer 3 switch enabling inter-VLAN routing with IP addresses between VLAN 10 and VLAN 20 in a Cisco network
CCNA August 25, 2019

Unlock Layer 3 Switches Mastery: Essential Cisco Guide for CCNA and CCNP Success in 2025

In the world of networking, understanding the OSI model’s Layer 3 is crucial for anyone preparing for CCNA (200-301) or CCNP Enterprise. This layer, known as the Network layer, handles logical addressing using protocols like IP and is responsible for packet forwarding between different networks, including path determination and routing through intermediate devices like routers....
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Network diagram for troubleshooting Inter-VLAN issues featuring Router01, Switch01, and VLAN-connected laptops.
CCNA August 25, 2019

Troubleshooting Inter-VLAN Issues – Briefly Explained

If you are using a legacy Inter-VLAN routing, ensure that the switch ports connecting to the router interface are configured in the correct VLAN. This is a very common issue with a switch port and requires troubleshooting. If a switch port is not configured to the correct VLAN, the devices on that VLAN cannot communicate...
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Diagram illustrating ping and traceroute for verifying inter-VLAN routing between Host1 (VLAN 100) and Host2 (VLAN 200) via a router with fa0/0 interface.
CCNA August 24, 2019

Verifying Inter-VLAN Routing Using Ping and Tracert Commands

Inter-VLAN routing enables communication between devices on different VLANs, a critical concept. Verifying host-to-host connectivity ensures proper configuration and operation of inter-VLAN routing. This article explores the ping and tracert utilities, essential tools for network engineers to test connectivity and troubleshoot issues. When configuring the Inter-VLAN routing, we must verify the host-to-host connectivity and data...
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CCNA August 24, 2019

Router-on-Stick Inter-VLAN Routing – Exclusive Explanation

In a previous lesson, legacy inter-VLAN routing requires multiple physical interfaces on the router and the switch. However, in the ‘Router-on-stick’ configuration, only one physical interface is needed on both sides. The Router-on-a-stick allows routing packets to subnets associated with VLANs connected to a router 802.1Q trunk. The Router-on-Stick uses a VLAN trunking configuration and...
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Network diagram illustrating Legacy Inter-VLAN Routing with a Cisco 2950 switch and a router, showing VLAN 100 (192.168.100.0/24) and VLAN 200 (192.168.200.0/24) connected via FastEthernet ports.
CCNA August 24, 2019

Master Legacy Inter-VLAN Routing (Updated 2025)

As we learned, each VLAN usually works on its own subnet. The network switches mainly work at layer 2 of the OSI model, so they do not examine the logical addresses. Therefore, for traffic between VLANs, inter-VLAN routing is required. The Legacy Inter-VLAN routing is the first solution for traffic between different VLANs. It relies...
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Diagram comparing Distance Vector and Link-State routing protocols, featuring routers, topology, routing tables, LSAs, and SPF algorithm — ideal for CCNA/CCNP learners.
CCNA August 24, 2019

What is Dynamic Routing Algorithms (Updated 2025)

Dynamic routing is a networking technique that provides optimal data routing. The network administrators and engineers configure a dynamic routing protocol on the network interfaces. The protocol running on the router learns about other routers automatically and also dynamically exchanges routing information with other routers. Dynamic routing protocols perform several activities, including network discovery and...
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CCNA August 24, 2019

Master How to configure Static Route – IPv4 and IPv6 (Updated 2025)

We can configure static or dynamic routes after configuring directly connected interfaces. Static routes are manually configured and provide a clear path between two networking devices. However, they must be manually reconfigured if the network topology changes, which is the main disadvantage of static routes. It is more secure and efficient than dynamic routes. It...
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Diagram illustrating Administrative Distance (AD) in Cisco networking with EIGRP (AD 90), OSPF (AD 110), and a table of default AD values for route sources.
CCNA August 23, 2019

What is Administrative Distance – Explain

In network environments, routers often receive multiple routes to the same destination from different sources, such as routing protocols (e.g., OSPF, EIGRP, RIP), static routes, or directly connected networks. To select the most trustworthy route, Cisco routers use Administrative Distance (AD), a critical concept in the Cisco Certified Network Associate (CCNA) curriculum. This article explains AD’s...
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Diagram illustrating equal-cost load balancing and EIGRP unequal-cost load balancing with routers R1, R2, and R3.
CCNA August 23, 2019

What is Network Load Balancing

Routers use administrative distance (AD) to prioritize routes learned from different routing protocols when multiple paths to a destination exist. AD is a value assigned to each routing protocol, with lower values indicating higher preference (e.g., EIGRP AD is 90, OSPF AD is 110). If multiple paths exist within the same protocol (same AD), the...
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