Ah, 802.1X authentication – a true veteran in network security, often affectionately (or sometimes exasperatedly) known as Dot1x. I remember configuring my first Dot1x setup way back in the day, and it felt like unlocking a new level of control…
When I first wrote about QinQ tunneling (or IEEE 802.1ad, formally known as Provider Bridging) back in 2011, it was an absolutely foundational technology for service providers. Fast forward to today, and while the network landscape has evolved dramatically with…
As a senior network engineer, I’ve witnessed firsthand the dramatic evolution of network technologies. While innovations like SD-WAN and cloud networking are now standard, fundamental concepts like MPLS remain vital, especially in service provider and large enterprise networks. Understanding MPLS…
OSPF /32 Issue in MPLS VPN Scenario: A Modern Troubleshooting and Automation Perspective =========================== Recently, while collaborating with a colleague on an MPLS Layer 3 VPN deployment, we encountered a deceptively simple issue that caused considerable head-scratching. It turned out…
As a network engineer, I often find myself fine-tuning routing protocols to optimize traffic flow and ensure network resilience. One of the fundamental ways we influence Open Shortest Path First (OSPF) behavior is through cost manipulation. While the core principles…
Hi guys! I’m back, and as always, it’s great to connect. Life, as a network engineer, often pulls us into deep dives and complex projects, but I always make it a point to share what I learn. Today, we’re revisiting…
The landscape of Border Gateway Protocol (BGP) reachability and robust network design has evolved considerably since this post was first published. While the fundamental principles remain, modern networks demand heightened attention to scalability, security, and observability. Let’s revisit a classic…
BGP Filtering Best Practices: Techniques and Guidelines for Using AS-Path Filters, Distribute-Lists, Prefix-Filters, and More.
Originally published back in 2011, this post introduced the essential concept of originating a default route in BGP. While the fundamental principles of BGP default route advertisement remain true, the landscape of network engineering, especially concerning automation, security, and advanced…
Today, revisiting a topic from my earlier lab days back in 2011, I found myself reflecting on EIGRP’s unequal cost load balancing. It’s a foundational concept in routing, and while network architectures have evolved dramatically, understanding these mechanisms remains crucial…