Reaction: Nerd Knobs and Open Source in Network Software

20 August 2018 | 1 Comment

This is an interesting take on where we are in the data networking world— Tech is commoditizing, meaning that vendors in the space are losing feature differentiation. That happens for a number of reasons, the most obvious of which is that you run out of useful features. Other reasons include the difficulty in making less-obvious…

Reaction: Network software quality

16 August 2018 | Comments Off on Reaction: Network software quality

Over at IT ProPortal, Dr Greg Law has an article up chiding the networking world for the poor software quality. To wit— When networking companies ship equipment out containing critical bugs, providing remediation in response to their discovery can be almost impossible. Their engineers back at base often lack the data they need to reproduce…

Research: Are We There Yet? RPKI Deployment Considered

13 August 2018 | Comments Off on Research: Are We There Yet? RPKI Deployment Considered

The Resource Public Key Infrastructure (RPKI) system is designed to prevent hijacking of routes at their origin AS. If you don’t know how this system works (and it is likely you don’t, because there are only a few deployments in the world), you can review the way the system works by reading through this post…

Research: Covert Cache Channels in the Public Cloud

6 August 2018 | Comments Off on Research: Covert Cache Channels in the Public Cloud

One of the great fears of server virtualization is the concern around copying information from one virtual machine, or one container, to another, through some cover channel across the single processor. This kind of channel would allow an attacker who roots, or otherwise is able to install software, on one of the two virtual machines,…

Research: Even Password Complexity is a Tradeoff

23 July 2018 | Comments Off on Research: Even Password Complexity is a Tradeoff

Stronger passwords are always better—at least this is the working theory of most folks in information technology, security or otherwise. Such blanket rules should raise your suspicions, however; the rule11 maxim if you haven’t found the tradeoff, you haven’t looked hard enough should apply to passwords, too. Dinei Florêncio, Cormac Herley, and Paul C. Van…

Thoughts on Impostor Syndrome

17 July 2018 | 1 Comment

How many times, on reading my blog, a book, or watching some video of mine over these many years (the first article I remember writing that was publicly available, many years ago, was the EIGRP white paper on Cisco Online, somewhere in 1997), have you thought—here is an engineer who has it all together, who…

Reaction: The Power of Open APIs

5 June 2018 | Comments Off on Reaction: The Power of Open APIs

Disaggregation, in the form of splitting network hardware from network software, is often touted as a way to save money (as if network engineering were primarily about saving money, rather than adding value—but this is a different soap box). The primary connections between disaggregation and saving money are the ability to deploy white boxes, and…

The Value of Community

4 June 2018 | Comments Off on The Value of Community

What seems, now, like a few short months ago, I was drawn into a small community known as The Network Collective. This last week, we launched our paid membership service. The first thing that must come to mind is that there will be training. Of course there will be training. A (minor) theme throughout the…

Why is the Feasibility Condition Less Than?

7 May 2018 | 1 Comment

A reader recently emailed me with this question: Why isn’t the condition for a Feasible Successor set to less than (B. D will immediately reroute to the FS, which is C, without changing the FC. This works, because C’s cost to 100::/64 via D is 4, much higher than it’s cost to 100::64 along C->A.…

The Universal Fat Tree

30 April 2018 | 5 Comments

Have you ever wondered why spine-and-leaf networks are the “standard” for data center networks? While the answer has a lot to do with trial and error, it turns out there is also a mathematical reason the fat-tree spine-and-leaf is is used almost universally. There often is some mathematical reason for the decisions made in engineering,…