One of my ExpertExpress engagements focused on networking in a future private cloud that might be built using OpenStack. The customer planned to deploy multiple data centers, and I recommended that they do everything they can to make sure they don’t make them a single failure domain.

Next step: translate that requirement into OpenStack terms.

A Technology Market Builder (in his own words) from a major networking vendor decided to publish a thought leadership article (in my sarcastic words) describing how Cisco’s embrace of complexity harmed the whole networking industry.

Let’s see how black this kettle-blaming pot really is ;), and make sure to have fun reading the comments to the original article.

Gabi Gerber (with a bit of help from my side) is organizing another set of SDN events in Zurich (Switzerland) in early June.

In the morning of June 7th we’ll talk about software-defined security:

An engineer working for a large system integrator sent me this question:

Since you are running a detailed series on leaf-and-spine fabrics these days, could you please suggest if following design scenarios of Facebook and Linkedin Data centers are also covered?

Short answer: No.

The moment an IETF working group agrees on a protocol someone starts creating extensions. PCEP is no exception; in the last part of the BGP-LS and PCEP webinar Julian Lucek talked about some of them.

One of my readers has customers that already experienced performance challenges with Tomahawk-based data center switches. He sent me an email along these lines:

My customers are concerned about buffer performance for packets that are 200 bytes and under. MORE IMPORTANTLY, a customer informed me that there were performance issues when running 4x25GE connections when one group of ports speaks to another group.

Reading the report Mellanox published not so long ago it seems there really is something fishy going on with Tomahawk.

The BGP-based SDN Solutions webinar triggered another interesting question from one the attendees:

It seems like the BGP route reflector functionality can be implemented as a Virtual Machine. Will a VM have enough resources to meet the requirements of a RR?

Short answer: Yes.

The featured webinar in May 2016 is the Overlay Virtual Networking webinar and in the featured videos (the ones marked with a star) you'll find introduction to overlay virtual networking and deep dive into flooding and MAC address learning in layer-2 overlay virtual networks.

One of my ExpertExpress engagements focused on BGP route maps and setting BGP attributes based on BGP communities, so I wanted to brush up my RouteMapFoo before the online session.

Here are a few (not-so-unexpected) results gathered from IOSv release 15.5(3)M.

Vendors that slapped API on top of their CLI are quick to claim that they SDN-enabled their boxes.

Not so fast. As I explained in SDN 101 webinar, programmable access to network devices is nice (less so when you're forced to use a vendor-specific API), but it's not SDN.

Here’s an interesting story I got from one of my friends:

• A large organization used a disaster recovery strategy based on stretched IP subnets and restarting workloads with unchanged IP addresses in a secondary data center;
• Once they experienced a WAN connectivity failure in the primary data center and their disaster recovery plan kicked in.

However, while they were busy restarting the workloads in the secondary data center, and managed to get most of them up and running, the DCI link unexpectedly came back to life.

I’m presenting at two Data Center Interest Group Switzerland events organized by Gabi Gerber in Zurich in early June:

• In the morning of June 7th we’ll talk about software-defined security, data center automation and open networking;
• In the afternoon of the same day (so you can easily attend both events) we’ll talk about VMware NSX microsegmentation and real-life implementations.

I hope to see you in Zurich in a bit more than a month!

My beloved source of meaningless marketing messages led me to a blog post with a catchy headline: are open-source SDN controllers ready for carrier-grade services?

It turned out the whole thing was a simple marketing gig for Ixia testers, but supposedly “the response of the attendees of an SDN event was overwhelming”, which worries me… or makes me happy, because it’s easy to see plenty of fix-and-redesign work in the future.

This must be old news to most of you (I managed to stay away from CLI for way too long), but I was pleasantly surprised that you can set terminal width (not just length) in Cisco IOS.

After listening to Open-Source Network Engineer Toolbox Nick Buraglio sent me an email saying “we should do another podcast on open-source network management tools…” and so we did. In Episode 56 of Software Gone Wild Nick, Elisa Jasinska and myself discussed a whole range of network management challenges and open-source tools you can use to address them.