This is an example of STP doing what it does best, and that is putting the Amber lit port 2 in "Blocking" state, to prevent a Switching Loop from forming. This is the logical Topology for a better idea of what's plugged into what: This post is focused on the "original" STP, all the fundamentals … Continue reading STP – Spanning-Tree Protocol Fundamentals, Root Bridge Election, BIDs and BPDUs, STP Port Roles / States!
*The image above is courtesy / cited by air-stream.org, so thanks to you guys! This particular demonstration appears to be using an STP cable (Shielded Twisted Pair), however there are other alternatives that can be used, including foils and types of screens to keep the low voltage (hopefully) working properly. As we know from CCNA, … Continue reading PoE Part 1 – The fundamentals with a dip into some more complex topics, and PoE working in action and explained exhaustively!
So to begin with Port Speeds and Duplexing and configuring ports manually for full / half duplexing and speeds - Just don't do it. I say that first, because now, I am going to say why you don't want to do it. With Autonegotiation configured on two ports, they will send what is called FLP's … Continue reading Adjusting Port Speeds, Duplexing, and Autonegotiation – Don’t do it!
I think that used to be my favorite questions on the old CCNA exam, because Security Device Manager was so intuitive to navigate the GUI, there is a similar tool ASDM for ASA's that can make life so much easier on them but getting that exact Java version / OS down for it to work … Continue reading SDM – Switching Database Manager Template configuration and demonstration (Not Security Device Mgr)!
Lets start from the verrrrry beginning of Switching time, when Dinosaurs roamed the internet. First came the Hub (and Bridge) that acted as one single Collision and Broadcast domain, so all nodes on the network used essentially a shared medium, which was made possible by something called CSMA/CD. What is CSMA/CD? I'm glad you asked. … Continue reading Switching Frame Decision – To Filter, Flood, or Forward as the MAC table is built, and a brief look at Layer 2 history!