DFS and Low Points

6 March 2018 | Comments Off on DFS and Low Points

On a recent history of networking episode, Alia talked a little about Maximally Redundant Trees (MRTs), and the concept of Depth First Search (DFS) numbering, along with the idea of a low point. While low points are quickly explained in my new book in the context of MRTs, I thought it worthwhile to revisit the…

Short Take: The Broadcom SDKLT Announcement

22 February 2018 | Comments Off on Short Take: The Broadcom SDKLT Announcement

My first short take at The Network Collective is up discussing the Broadcom SDKLT announcement. Does this really mean the end of vendors or network engineering? You can guess my answer, or you can watch the video and hear it for yourself.

The DNS Negative Cache

13 February 2018 | Comments Off on The DNS Negative Cache

Considering the DNS query chain— A host queries a local recursive server to find out about banana.example The server queries the root server, then recursively the authoritative server, looking for this domain name banana.example does not exist There are two possible responses in this chain of queries, actually. .example might not exist at all. In…

History of Networking: Paul Vixie on the Origins of DNS

6 February 2018 | Comments Off on History of Networking: Paul Vixie on the Origins of DNS

Paul Vixie joins us on the History of Networking to talk about the spread of the DNS system—like a virus through the body network. All those radios in the background at a bit of history; Paul is an Amateur Radio Operator of many years, though, like me, he is not as active as he used…

Some Market Thoughts on the Broadcom SDKLT

5 February 2018 | Comments Off on Some Market Thoughts on the Broadcom SDKLT

Broadcom, to much fanfare, has announced a new open source API that can be used to program and manage their Tomahawk set of chips. As a general refresher, the Tomahawk chip series is the small buffer, moderate forwarding table size hardware network switching platform on which a wide array of 1RU (and some chassis) routers…

The Overoptimization Meltdown

15 January 2018 | 1 Comment

In simple terms Meltdown and Spectre are simple vulnerabilities to understand. Imagine a gang of thieves waiting for a stage coach carrying a month’s worth of payroll. There are two roads the coach could take, and a fork, or a branch, where the driver decides which one to take. The driver could take either one.…

The Humble API

2 January 2018 | Comments Off on The Humble API

Network Engineering and coding, like many other things in the information technology world, share overlapping concepts—even if we don’t often recognize the overlap because we are too busy making up new names to describe the same thing. For this week’s video, I turn my attention to the Application Programming Interface, or the API.


5 December 2017 | 1 Comment

When deploying IPv6, one of the fundamental questions the network engineer needs to ask is: DHCPv6, or SLAAC? As the argument between these two has reached almost political dimensions, perhaps a quick look at the positive and negative attributes of each solution are. Originally, the idea was that IPv6 addresses would be created using stateless…

What is a Tunnel

7 November 2017 | Comments Off on What is a Tunnel

It’s a bird! It’s a plane! It’s a… tunnel? In this video, I take on the age old question: what is a tunnel? Is it a protocol, or is it something else? This was cross posted to Network Computing

Video: SDN versus Automation

31 October 2017 | 3 Comments