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 three-step process of configuring IPv6 ACLs, including creating a named ACL, using permit or deny statements, and applying to an interface.
CCNA September 22, 2019

Understanding IPv6 ACLs Configuration: Step-by-Step Guide

Access Control Lists (ACLs) are a fundamental component of network security, and understanding IPv6 ACLs is essential for CCNA and CCNP certification candidates. As networks transition from IPv4 to IPv6 to accommodate the growing number of devices, mastering IPv6 ACL configuration is critical for securing modern networks. This comprehensive guide explains IPv6 ACLs, compares them […]
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Understanding ACL Errors in Cisco Networks
CCNA September 22, 2019

How to Troubleshoot ACL Errors

Access Control Lists (ACLs) are fundamental to network security and traffic management in Cisco environments. However, misconfigurations can lead to ACL errors, blocking legitimate traffic or allowing unauthorized access. This article explores common ACL errors with examples, focusing on troubleshooting techniques using show commands. Understanding these errors is crucial for passing certification exams and excelling […]
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A clipboard with green checkmarks and red Xs next to the text "ACL Logics" on a blue background.
CCNA September 21, 2019

Inbound and Outbound ACL Logic

Access Control Lists (ACLs) are a fundamental component of Cisco networking, used to filter traffic based on predefined rules. For CCNA and CCNP students, mastering ACLs is critical for securing networks and passing certification exams. ACLs allow network engineers to permit or deny packets based on criteria like source and destination IP addresses, protocols, and […]
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Diagram illustrating Extended ACLs with permit and deny rules for IP ranges 192.168.2.0 and 192.168.2.123, showing network traffic control.
CCNA September 21, 2019

How to Configure Extended ACLs – Exclusive Explanation

The number of extended ACLs ranges from 100 to 199 and 2000 to 2699, providing 799 possible numbered ACLs. The 100-199 range was historically used, while 2000-2699 is recommended for modern networks due to greater flexibility and support for named ACLs. Choose based on your network’s complexity and Cisco IOS version. We can also create […]
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Illustration of social engineering with two silhouetted figures using a phone and laptop, surrounded by social media icons and lock symbols on a circuit-like background.
Cyber Security September 14, 2019

What Is Social Engineering in Cybersecurity? Types, Examples, and Prevention Strategies (2025 Guide)

Social engineering remains one of the most effective tactics in a cybercriminal’s arsenal, accounting for 36% of initial access vectors in incident response cases between May 2024 and May 2025. It’s a psychological manipulation technique where attackers exploit human behavior to gain unauthorized access to information, systems, or physical locations—without relying on code or exploits. […]
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Illustration of browser security threats featuring a globe icon, a masked hacker, and ad symbols on a blue background.
Cyber Security September 14, 2019

Browser Plugins and Poisoning: Risks, Exploits, and Defenses in Cybersecurity

Security backdoors and vulnerabilities can severely impact web browsers, leading to unwanted pop-up ads, collection of personal data, or installation of adware, viruses, or spyware. Cybercriminals often target a browser’s executable files, core components, and browser plugins to gain unauthorized access. Browser Plugins A browser plugin (now often called an extension or add-on in modern […]
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Infographic illustrating vishing, smishing, pharming, and whaling cyber threats with icons of a speaking person, hooked computer, poisoned phone message, and business executive.
Cyber Security September 14, 2019

Vishing, Smishing, Pharming, and Whaling in Cybersecurity: Definitions, Examples, and Prevention Tips

In the ever-evolving landscape of cybersecurity, social engineering attacks like vishing, smishing, pharming, and whaling continue to exploit human vulnerabilities alongside network weaknesses. According to the 2025 Verizon Data Breach Investigations Report, phishing variants account for over 30% of breaches, with vishing and smishing rising due to mobile and VoIP adoption. As a network engineer, […]
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Illustration of phishing scam with hooked email envelope, laptop, credit card, shield, and lock symbolizing cyber threats and security.
Cyber Security September 14, 2019

What Is Phishing? A Comprehensive Guide for Cybersecurity Enthusiasts (Updated 2025)

As discussed in previous articles on network security, phishing remains a low-effort, high-reward tactic for cybercriminals. They send fake emails, text messages, or create authentic-looking websites to steal personal and financial data. This technique, also known as spoofing, involves forging email headers or IP addresses to mimic trusted sources, often evading basic network filters like […]
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Threats to network security illustrated with spyware mask, adware monitor, and scareware warning icons on a dark blue background.
Cyber Security September 13, 2019

Understanding Spyware, Adware, and Scareware: A Cybersecurity Guide for Enthusiasts

In the previous article, I discussed malware, including its types: viruses, worms, ransomware, Trojan horses, logic bombs, back doors, and rootkits. This article dives deeper into additional malware types—spyware, adware, and scareware—focusing on their mechanics, network implications, and real-world impacts. As a network engineer with years of experience in cybersecurity, I’ll emphasize how these threats […]
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Illustration of a smartphone displaying a spam email notification with the title 'Identifying SPAM MAIL'
Cyber Security September 13, 2019

Identifying Spam Mail: A Comprehensive Cybersecurity Guide for 2025

Email remains a universal service for billions worldwide, serving as one of the most popular communication tools. However, its widespread use comes with significant vulnerabilities, making it a prime target for cybercriminals. These unsolicited messages, commonly known as “junk mail” or spam, are predominantly sent by advertisers or malicious actors. Criminals exploit spam to distribute […]
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