The Hedge 8: Open Source and the Future of Routing Software
Almost every company relies on open source software in some way, which leads to the natural question—how will the heart of the network, routing and switching, be impacted by open source software? In this episode of the Hedge, Sue Hares, Donald Sharp, and Russ White discuss the current and future world of open source routing software. Donald is one of the main drivers of the FR Routing open source routing stack; Russ White is a maintainer on the project and is still deeply involved in commercial routing software, and Sue Hares was deeply involved in the origins of the GateD open source routing stack.
Service Provider Tech Doesn’t Apply?
Service provider problems are not your problems. You should not be trying to solve your problems the same way service providers do.
This seems intuitively true—after all, just about everything about a train or a large over-the-road truck (or lorry) is different from a passenger car. If the train is the service provider network and the car is the “enterprise” network, it seems to be obvious the two have very little in common.
Or is it?
What this gets right is that if an operator sells access to their network, or a single application, their network is likely to be built differently than the more general-purpose designs used in organizations that must support a wide range of applications and purposes. These differences are likely to show up in the choice of hardware, how the network is operated, and the kinds of services offered (or not).
The Hedge 7: Leslie Daigle and Internet Invariants
Some things always change, and some things never change. In this episode of the Hedge, Leslie Daigle joins Phill Simonds and Russ White to discuss her research into the things that do not change—and whether or not those things really have changed over the years since her original report for the Internet Society on Internet invariants.
Is it planning… or just plain engineering?
Over at the ECI blog, Jonathan Homa has a nice article about the importance of network planning–
Jonathan describes why this is so–traffic is constantly increasing, and the choice of tools we have to support the traffic loads of today and tomorrow can be classified in two ways: slim and none (as I remember a weather forecaster saying when I “wore a younger man’s shoes”). The problem, however, is not just tools. The network is increasingly seen as a commodity, “pure bandwidth that should be replaceable like memory,” made up of entirely interchangeable parts and pieces, primarily driven by the cost to move a bit across a given distance.
Autonomic, Automated, and Reality
Once the shipping department drops the box off with that new switch, router, or “firewall,” what happens next? You rack it, cable it up, turn it on, and start configuring, right? There are access to controls to configure—SSH, keys, disabling standard accounts, disabling telnet—interface addresses to configure, routing adjacencies to configure, local policies to configure, and… After configuring all of this, you can adjust routing in the network to route around the new device, and then either canary the device “in production” (if you run your network the way it should be run), or find some prearranged maintenance time to bring the new device online and test things out. After all of this, you can leave the new device up and running in the network, and move on to the next task.
Until it breaks.
The Hedge 6: Geoff Huston on DoH
In this episode of the Hedge, Geoff Huston joins Tom Ammon and I to finish our discussion on the ideas behind DNS over HTTPS (DoH), and to consider the implications of its widespread adoption. Is it time to bow to our new overlords?
The Hedge 5: Geoff Huston on DoH
In this episode of the Hedge, Geoff Huston joins Tom Ammon and I to discuss the ideas behind DNS over HTTPS (DoH), and to consider the implications of its widespread adoption. Is it time to bow to our new overlords?
Stop Using the OSI Model
We all use the OSI model to describe the way networks work. I have, in fact, included it in just about every presentation, and every book I have written, someplace in the fundamentals of networking. But if you have every looked at the OSI model and had to scratch your head trying to figure out how it really fits with the networks we operate today, or what the OSI model is telling you in terms of troubleshooting, design, or operation—you are not alone. Lots of people have scratched their heads about the OSI model, trying to understand how it fits with modern networking. There is a reason this is so difficult to figure out.
The OSI Model does not accurately describe networks.
What set me off in this particular direction this week is an article over at Errata Security:
The Hedge 4: Joe Cozzupoli
Multicloud is all the rage — but is this always an intentional state of affairs, or do companies just “fall into” multicloud? Security in multicloud and certifications round out this episode of the Hedge, where we are joined by Joe Cozzupoli. You can get in touch with Joe through twitter at @jcozzupo24150.
DNS Query Minimization and Data Leaks
When a recursive resolver receives a query from a host, it will first consult any local cache to discover if it has the information required to resolve the query. If it does not, it will begin with the rightmost section of the domain name, the Top Level Domain (TLD), moving left through each section of the Fully Qualified Domain Name (FQDN), in order to find an IP address to return to the host, as shown in the diagram below.
This is pretty simple at its most basic level, of course—virtually every network engineer in the world understands this process (and if you don’t, you should enroll in my How the Internet Really Works webinar the next time it is offered!). The question almost no-one ever asks, however, is: what, precisely, is the recursive server sending to the root, TLD, and authoritative servers?