One of my readers sent me this question:

I'm researching NFV/SDN and wonder if the software L2 switches support spanning tree.

TL&DR: Some do, some don’t.

Online webinars are great, but many engineers still prefer live workshops – they’re an excellent opportunity for unrestricted 2-way communication and exchange of ideas – so I decided to turn a few of my best webinars (or webinar tracks) into workshops, and Gabi Gerber, the wonderful organizer of Data Center days in Switzerland took over the logistics, resulting in the first-ever Data Center Fabrics workshop in Zurich in late March.

In theory, you should shut down a network device with a well-defined procedure:

• Drain the traffic from the device;
• Verify the device is no longer forwarding traffic;
• Turn off the device.

In practice, network devices don’t have a shutdown command, and reload typically just restarts the network OS.

A while ago I watched a Networking Field Day Extra video in which Chris Young and Michael Zayats talked about HP’s open source initiative – they decided to build yet another open networking operating system.

Obviously I wanted to know more, reached out to Chris, and we quickly managed to set up an online chat resulting in Episode 48 of Software Gone Wild podcast.

A few weeks ago I got into an interesting discussion about the potential harm caused by unnumbered IPv4/IPv6 interfaces.

Ignoring for the moment the vendor-specific or media-specific implementation details, these two arguments usually pop up in the first 100 milliseconds (assuming engineers involved in the discussion have some hands-on operational experience):

John wrote an optimistic comment to my fashionable designs rant:

Nobody in their right mind does "fashionable" things when dealing with infrastructures that are required to be solid, dependable and robust.

Unfortunately many enterprises aren’t that prudent – the last Expert Express engagement I had in 2015 was yet another customer who lost two major data centers due to a bridging loop spilling over a stretched VLAN infrastructure.

As you know I always promise my loyal subscribers at least 6 new webinars per year. Well, 2015 was a bit more fruitful. Let’s start with the easy ones:

• There was the regular Data Center Fabrics update webinar in May with guest speaker Dinesh Dutt from Cumulus Networks;
• IPv6 microsegmentation webinar in March extended the IPv6 curriculum;
• Michele Chubirka had a great webinar on open-source security tools in September;
• The Designing Active-Active and Disaster Recovery Data Centers completed the first phase of the cloud building curriculum (more to come in 2016);

However, I spent most of my time developing the SDN and network automation curriculum:

I was often asked about two emerging technologies that enable standard controller-based WAN traffic engineering: BGP-LS to extract the network topology and PCEP to establish end-to-end tunnels from a controller.

Unfortunately, I never found time to explore these emerging technologies and develop a webinar. However, after Julian Lucek from Juniper did such a great job on the NorthStar podcast, I asked him whether he would be willing to do a deep dive technology webinar on the two technologies and he graciously agreed to do it.

The number of visits to my web site is slowly going down – you’re giving me a very clear signal that it’s time to stop blogging.

I hope you’ll manage to catch at least a few quiet days with your loved ones and I wish you all the best in 2016!

More in 3 weeks or so ;)

Juniper recently launched their Tomahawk-based switch (QFX5200) and included a lot of information on the switching hardware in one of their public presentations (similar to what Cisco did with Nexus 9300), so I got a non-NDA glimpse into the latest Broadcom chipset.

You’ll get more information on QFX5200 as well as other Tomahawk-based switches in the Data Center Fabrics Update webinar in spring 2016.

Here’s what I understood the presentation said:

If you have some leftover training budget for 2015, there’s no better way to spend it than to invest it in a workgroup ipSpace.net subscription ;)

You can choose between two standard packages (6 or 21 users) which include online consulting sessions, or create your own customized package.

Finally, if you plan to buy one of the standard packages, hurry up – the Dec15 promotional code gives you 10% discount till the end of the year.

Nick Buraglio used OpenDaylight and OpenFlow-enabled switches to build a part of the exhibition network of a large international supercomputing conference and was kind enough to talk about his real-life experience in Episode 47 of Software Gone Wild.

We covered:

When I wrote a blog post explaining the difference between centralized control and centralized control plane, John Casey, CEO of CPLANE Networks wrote a comment saying “yeah, that’s exactly what we’re doing.”

It took us a while to get the stars aligned, but finally we managed to sit down and chat about what they’re doing, resulting in Episode 46 of Software Gone Wild.

Nuno wrote an interesting comment to my Stretched Firewalls across L3 DCI blog post:

You're an old school, disciplined networking leader that architects networks based on rock-solid, time-tested designs. But it seems that the prevailing fashion in network design and availability go against your traditional design principles: inter-site firewall clustering, inter-site vMotion, DCI, etc.

Not so fast, my young padawan.

Let’s define prevailing fashion first. You might define it as Kool-Aid id peddled by snake oil salesmen or cool network designs by people who know what they’re doing. If we stick with the first definition, you’re absolutely right.

Now let’s look at the second camp: how people who know what they’re doing build their network (Amazon VPC, Microsoft Azure or Bing, Google, Facebook, a number of other large-scale networks). You’ll find L3 down to ToR switch (or even virtual switch), and absolutely no inter-site vMotion or clustering – because they don’t want to bet their service, ads or likes on the whims of technology that was designed to emulate thick yellow cable.

This isn't the first time that readers have asked you about these technologies, and it won't be the last. Vendors will continue to market them despite their shortcomings, and customers will continue to eat them up.

As long as there will be someone willing to believe in fairy tales and Santa Claus, there will be someone dressed in red coat and fake beard yelling “Ho, Ho, Ho!”

Enterprise IT managers sometimes act like small kids. They don’t want to hear that they have people- and process problems, and love to believe that the next magical bit of technology will solve whatever it is that bothers them. Vendors obviously love to explore these cravings and sell them ever-more-complex solutions.

I'd like to think that vendors will also continue to work out the kinks and over time the technology will become rock solid and time-tested.

I am positive you can make any technology almost-rock-solid. You can also make pigs fly (see RFC 1925 sect. 2.3). However, have you included the fuel costs in your TCO?

Also, the more complex a technology is, the likelier it is to crash down like a house of cards, and you’ll be left with an incomprehensible mix of bits and pieces that will be impossible to put back together (see also: You can’t reformat your data center).

Nino concluded his comment with a question:

Are you too stuck on past, traditional designs and not being open to new ways of building IT? I get that IT is very cyclical, and these new trends may die in the future...or thrive, and the customers may either fail...or succeed.

I am very open to new ways of building IT. I preach the need for meaningful SDN (not the centralized control plane crap), network automation, and proper application architecture. I just refuse to believe in fairy tales, and solving non-technical problems with technology.

Finally…

Looking for more red pills? Explore my SDN webinars, Designing Active/Active Data Centers webinar, and vMotion-related blog posts.

The featured webinar of December 2015 is vSphere 6 Networking, a 6-hour deep dive into vSphere 6 networking features covering almost every single vSphere network-related feature.

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