The EIGRP SIA Incident: Positive Feedback Failure in the Wild

9 April 2018 | Comments Off on The EIGRP SIA Incident: Positive Feedback Failure in the Wild

Reading a paper to build a research post from (yes, I’ll write about the paper in question in a later post!) jogged my memory about an old case that perfectly illustrated the concept of a positive feedback loop leading to a failure. We describe positive feedback loops in Computer Networking Problems and Solutions, and in…

Troubleshooting: Half Split

16 May 2017 | Comments Off on Troubleshooting: Half Split

The best models will support the second crucial skill required for troubleshooting: seeing the system as a set of problems to be solved. The problem/solution mindset is so critical in really understanding how networks really work, and hence how to troubleshoot them, that Ethan Banks and I are writing an entire book around this concept.…

Troubleshooting: Models

9 May 2017 | Comments Off on Troubleshooting: Models

How well can you know each of these four systems? Can you actually know them in fine detail, down to the last packet transmitted and the last bit in each packet? Can you know the flow of every packet through the network, and every piece of information any particular application pushes into a packet, or…

Troubleshooting: Basics

2 May 2017 | Comments Off on Troubleshooting: Basics

It’s 2AM, the network is down, and the CEO is on the phone asking when it is going to be back up—the overnight job crucial to the business opening in the morning has failed, and the company stands to lose millions of dollars if the network is not fixed in the next hour or so.…