Everyone Must Learn to Code
The word on the street is that everyone—especially network engineers—must learn to code. A conversation with a friend and an article passing through my RSS reader brought this to mind once again—so once more into the breach. Part of the problem here is that we seem to have a knack for asking the wrong question. When we look at network engineer skill sets, we often think about the ability to configure a protocol or set of features, and then the ability to quickly troubleshoot those protocols or features using a set of commands or techniques.
The Hedge 51: Tim Fiola and pyNTM
Have you ever looked at your wide area network and wondered … what would the traffic flows look like if this link or that router failed? Traffic modeling of this kind is widely available in commercial tools, which means it’s been hard to play with these kinds of tools, learn how they work, and understand how they can be effective. There is, however, an open source alternative—pyNTM. While this tool won’t replace a commercial tool, it can give you “enough to go on” for many network operators, and give you the experience and understanding needed to justify springing for a commercial product.
It Has to Work (RFC1925, Rule 1)
According to RFC1925, the first fundamental truth of networking is: it has to work. While this might seem to be overly simplistic, it has proven—over the years—to be much more difficult to implement in real life than it looks like in a slide deck. Those with extensive experience with failures, however, can often make a better guess at what is possible to make work than those without such experience. The good news, however, is the experience of failure can be shared, especially through self-deprecating humor.
Understandability
According to Maor Rudick, in a recent post over at Cloud Native, programming is 10% writing code and 90% understanding why it doesn’t work. This expresses the art of deploying network protocols, security, or anything that needs thought about where and how. I’m not just talking about the configuration, either—why was this filter deployed here rather than there? Why was this BGP community used rather than that one? Why was this aggregation range used rather than some other? Even in a fully automated world, the saying holds true.
The Hedge 49: Karen O’Donoghue and Network Time Security
Time is critical for many of the systems that make the Internet and other operational networks “go,” but we often just assume the time is there and it’s right. In this episode of the Hedge, Karen O’Donoghue joins Alvaro and Russ to talk about some of the many attacks and failures that can be caused by an incorrect time, and current and ongoing work in securing network time in the IETF.
The Hedge 50: The Challenge of Growing People
Many network engineers complain about their companies not giving them opportunities—but how many think about helping the company grow in a way that allows them to have the opportunities they desire? Scott Morris, aka “evil ccie,” joins Tom and Russ on this episode of the Hedge to talk about the challenges of certifications, growing people, and people learning how to grow in a way what improves the business. Sometimes growing means creating opportunities rather than just waiting for them to knock.
Technologies that Didn’t: The Fiber Distributed Data Interface
Token Ring, in its original form, was—on paper—a very capable physical transport. For instance, because of the token passing capabilities, it could make use of more than 90% of the available bandwidth. In contrast, Ethernet systems, particularly early Ethernet systems using a true “single wire” broadcast domain, cannot achieve nearly that kind of utilization—hence “every device on its own switch port.” The Fiber Distributed Data Interface, or FDDI, is like Token Ring in many ways. For instance, FDDI uses a token to determine when a station connected to the ring can transmit, enabling efficient use of bandwidth.
And yet, Ethernet is the common carrier of almost all wired networks today, and even wireless standards mimic Ethernet’s characteristics. What happened to FDDI?
The White Board and the Simulation
In the argument between OSPF and BGP in the data center fabric over at Justin’s blog, I am decidedly in the camp of IS-IS. Rather than lay my reasons out here, however (a topic for another blog post?), I want to focus on something else Justin said that I think is incredibly important for network engineers to understand.
I think whiteboards are the most important tool for network design currently available, which makes me sad. I wish that wasn’t true, I want much better tools. I can’t even tell you the number of disasters averted by 2-3 great network engineers arguing over a whiteboard.
The Hedge 48: Chris Romeo and the State of Security
Chris Romeo is a famous application security expert who has spent the last several years building a consulting and training company called Security Journey. Chris joins Tom and Russ to talk about the state of security and what network engineers need to know about security from an application perspective.
Unsolicited Multicast: Random Thoughts on the LFN White Paper
A short while back, the Linux Foundation (Networking), or LFN, published a white paper about the open source networking ecosystem. Rather than review the paper, or try to find a single theme, I decided to just write down “random thoughts” as I read through it. This is the (rather experimental) result.