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: