Russ

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Hedge 197: Old Engineering Books (1)

It’s time for the October Roundtable! This month Eyvonne, Tom, and Russ are reading quotes from an engineering book published in 1911 and reacting to them. How much has engineering changed? How much has engineering stayed the same? How well can advice from a hundred years ago apply to modern engineering problems and life? It turns out that, in spite of their faults, there is a lot of great wisdom in these old books.

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Simple or Complex?

A few weeks ago, Daniel posted a piece about using different underlay and overlay protocols in a data center fabric. He says:

There is nothing wrong with running BGP in the overlay but I oppose to the argument of it being simpler.

One of the major problems we often face in network engineering—and engineering more broadly—is confusing that which is simple with that which has lower complexity. Simpler things are not always less complex. Let me give you a few examples, all of which are going to be controversial.

When OSPF was first created, it was designed to be a simpler and more efficient form of IS-IS. Instead of using TLVs to encode data, OSPF used fixed-length fields. To process the contents of a TLV, you need to build a case/switch construction where each possible type a separate bit of code. You must count off the correct length for the type of data, or (worse) read a length field and count out where you are in the stream.

Fixed-length fields are just much easier to process. You build a structure matching the layout of the fixed-length fields in memory, then point this structure at the packet contents in-memory. From there, Continue reading

Schedule 0923

Here’s a preview of what I’m working on for those who are interested:

  • September 2023: (this Friday) How Routers Really Work, a three-hour live webinar at Safari Books Online through Pearson
  • October 2023:
    • How the Internet Really Works a four-hour live webinar at Safari Books Online through Pearson; this is newly formatted and reorganized version of the two sessions I used to do
    • I’m speaking at a small theological conference on AI and ethics in Cary, NC
  • November 2023:
    • The new CCST book should be released
    • I have recorded a network basics video series that should be released in late 2023 or early 2024
  • January 2024:
    • What Coders Need to Know about Networks, a new course, co-authored with an engineer from Akamai; a three-hour live webinar at Safari Books Online through Pearson
    • I’ll be teaching a course in network engineering at the University of Colorado for the spring semester
  • February 2024: A new three-hour live webinar on infrastructure interviewing skills at Safari Books Online through Pearson
  • March 2024: BGP Policy, a three-hour live webinar on Safari Books Online through Pearson
  • April 2024: Troubleshooting, a reformatted and rebuilt three-hour live webinar at Safari Books Online through Pearson

There will probably Continue reading

Upcoming Training: How Routers Really Work

Have you ever wondered exactly how a router moves a packet from input to output interface? Or what the difference between is between a router’s and host’s operating system? Or why forwarding engines are built in classes, and one forwarding engine cannot “do it all?” Join me on the 22nd at 1pm ET for How Routers Really Work, a three-hour tour through router guts. I’ve replaced about 10% of the slides since the last time I taught this course.

If you register, you can watch the recording at a later date.

Register here.

Hedge 194: Network Automation with the Network Automation Forum

Year after year network engineering media, vendors, and influencers talk about the importance of network automation—and yet according to surveys, most network operators still have not automated their network operations. In this episode of the Hedge, part 2 of 2, Chris Grundemann and Scott Robohn join the Hedge to give their ideas on why network automation isn’t happening, and how we can resolve the many blockers to automation.

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Hedge 193: Network Automation with the Network Automation Forum

Year after year network engineering media, vendors, and influencers talk about the importance of network automation—and yet according to surveys, most network operators still have not automated their network operations. In this episode of the Hedge, part 1 of 2, Chris Grundemann and Scott Robohn join the Hedge to give their ideas on why network automation isn’t happening, and how we can resolve the many blockers to automation.

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To find out more about the Network Automation Forum and their upcoming meeting, check out their web site.

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