Master DNS Basics Fast with Chris Greer

In this engaging video, networking expert Chris Greer takes viewers on a hands-on journey through the fundamentals of DNS (Domain Name System). Starting with the basics, he explains how DNS acts as the internet's phonebook, translating user-friendly domain names like wireshark.org into machine-readable IP addresses. Using simple tools like the nslookup command and Wireshark for packet capturing, Greer demonstrates a real DNS query in action, breaking down the four key packets involved: the initial UDP query to the resolver and the response with resolved IP addresses. He dives into essential details such as transaction IDs for matching requests and responses, recursion flags, and TTL (Time to Live) values that keep resolutions fresh in a dynamic online world.

from the web: Using Wireshark to analyze TCP SYN/ACKs to find TCP connection failures and latency issues.

In this video Mike goes through how to use Wireshark display filters and the conversation matrix to identify failed TCP connections and measure the roundtrip delay between the client and the server.

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Telnet vs SSH

Who Invited This access-point?

Monitoring your Wi-Fi network isn’t just for giant enterprises with blinking racks of gear—it’s just as important for small offices and home labs. Systems like Ubiquiti UniFi don’t just move packets around; they actively watch what’s happening in your wireless environment and throw up alerts when something looks fishy. That “third-party access point broadcasting the same SSID” warning is a perfect example of your network politely saying, “Uh, hey… this doesn’t look like one of ours.”

At first glance, a duplicate SSID might seem harmless. Maybe a neighbor named their Wi-Fi the same thing as yours, or someone plugged in a cheap router without telling you. But in practice, this can cause real problems. Client devices can roam to the wrong access point, leading to slow speeds, dropped connections, or users getting kicked off the network for no obvious reason. Worse, if that rogue access point isn’t secured properly, it can become a security risk or even a sneaky man-in-the-middle opportunity.

Stanford free AI course - Transformers & LLMs (CME295)

If you’re fascinated by cutting-edge artificial intelligence and want to understand one of the most transformative technologies in modern AI, the Transformers YouTube playlist from Stanford Online is a must-watch resource. This thoughtfully curated playlist brings together videos that dive deep into Transformer architectures — the foundations behind powerful models like GPT and BERT that power natural language understanding and generation today. (YouTube)

What sets this playlist apart is its academic quality combined with accessible explanations. The content is delivered by Stanford educators and researchers, giving you insights directly from one of the world’s leading institutions in AI research. Whether you’re a student, a developer, or simply an enthusiast eager to stay ahead in the AI revolution, these videos break down complex ideas like self-attention and sequence modeling in ways that are both clear and engaging. (YouTube)

from the web : Why use a route map for redistribution?

The post explains why using a route-map when redistributing routes between protocols (like RIPv2 into OSPF) is important: without one, a router will redistribute all routes indiscriminately, which can cause routing loops, security issues, or unintended route propagation. A route-map gives fine control over which prefixes are shared and allows modification of route attributes such as metrics, metric types, and tags before redistribution. The article walks through a lab topology where RIPv2 routes from one router are selectively redistributed into an OSPF domain using access lists and a route-map that sets different metrics for specific prefixes, demonstrating the configuration and the resulting routing table.