Keith’s Law (1)

28 September 2021 | Comments Off on Keith’s Law (1)

I sometimes reference Keith’s Law in my teaching, but I don’t think I’ve ever explained it. Keith’s Law runs something like this:

Any large external step in a system’s capability is the result of many incremental changes within the system.

Thoughts on the Collapsed Spine

21 September 2021 |

One of the designs I’ve been encountering a lot of recently is a “collapsed spine” data center network, as shown in the illustration below.

Russ’ Rules of Network Design

14 September 2021 | Comments Off on Russ’ Rules of Network Design

We have the twelve truths of networking, and possibly Akin’s Laws, but is there a set of rules for network design? I couldn’t find one, so I decided to create one, containing 18 laws I’ve listed below.

Marketing Wins

30 August 2021 | Comments Off on Marketing Wins

Off-topic post for today …

In the battle between marketing and security, marketing always wins. This topic came to mind after reading an article on using email aliases to control your email—

For example, if you sign up for a lot of email newsletters, consider doing so with an alias. That way, you can quickly filter the incoming messages sent to that alias—these are probably low-priority, so you can have your provider automatically apply specific labels, mark them as read, or delete them immediately.

It always takes longer than you think

23 August 2021 | Comments Off on It always takes longer than you think

Everyone is aware that it always takes longer to find a problem in a network than it should. Moving through the troubleshooting process often feels like swimming in molasses—you’re pulling hard, and progress is being made, but never fast enough or far enough to get the application back up and running before that crucial deadline. The “swimming in molasses effect” doesn’t end when the problem is found out, either—repairing the problem requires juggling a thousand variables, most of which are unknown, combined with the wit and sagacity of a soothsayer to work with vendors, code releases, and unintended consequences.

The Centralization of the Internet

16 August 2021 | Comments Off on The Centralization of the Internet

My article on Internet centralization just published over at The Public Discourse—

Most of the Internet’s traffic now flows through the networks of a few large companies rather than a multitude of small transit providers, and the Internet’s physical infrastructure is being reshaped to meet this new reality. But relying on a few providers to host all the content on the Internet makes it possible for just a few companies to shut down entire services or control speech.

The Grass is Always Greener

9 August 2021 |

This last week I was talking to someone at a small startup that intends to eliminate all the complex routing from campus networks. In the past, when reading blog posts about Kubernetes, I’ve read about how it was designed to eliminate routing protocols because “routing protocols are so complex.”

Color me skeptical.

It Always Takes Too Long

2 August 2021 | Comments Off on It Always Takes Too Long

It always takes longer to find a problem than it should. Moving through the troubleshooting process often feels like swimming in molasses—it’s never fast enough or far enough to get the application back up and running before that crucial deadline. The “swimming in molasses effect” doesn’t end when the problem is found out, either—repairing the problem requires juggling a thousand variables, most of which are unknown, combined with the wit and sagacity of a soothsayer to work with vendors, code releases, and unintended consequences.

Leveraging Similarities

26 July 2021 | Comments Off on Leveraging Similarities

We tend to think every technology and every product is roughly unique—so we tend to stay up late at night looking at packet captures and learning how to configure each product individually, and chasing new ones as if they are the brightest new idea (or, in marketing terms, the best thing since sliced bread). Reality check: they aren’t. This applies across life, of course, but especially to technology.

Whatever it is, you need more (RFC1925 rule 9)

19 July 2021 | Comments Off on Whatever it is, you need more (RFC1925 rule 9)

There is never enough. Whatever you name in the world of networking, there is simply not enough. There are not enough ports. There is not enough speed. There is not enough bandwidth. Many times, the problem of “not enough” manifests itself as “too much”—there is too much buffering and there are too many packets being dropped. Not so long ago, the Internet community decided there were not enough IP addresses and decided to expand the address space from 32 bits in IPv4 to 128 bits in IPv6.