Category: Data Center

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.

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.

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.

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.

A month ago I published the video where I described the idea that “two switches is all you need in a medium-sized data center”. Now let’s dig into the details: the first step you have to take to optimize your data center infrastructure is to virtualize all servers.

For even more details, watch the Designing Private Cloud Infrastructure webinar, or register for the Building Next-Generation Data Center course.

Mark Baker left this comment on my Stretched Firewalls across Layer-3 DCI blog post:

Strange how inter-DC clustering failure is considered a certainty in this blog.

Call it experience or exposure to a larger dataset. Anything you build will eventually fail; just because you haven’t experienced the failure yet doesn’t mean that the system will never fail but only that you were lucky so far.

When I started thinking about my first online course, I decided to create something special – it should be way more than me talking about cool new technologies and designs – and the guest speakers are a crucial part of that experience.

The first guest speaker is one of the gurus of network design and complexity, wrote numerous books on the topic, and recently worked on a hardware-independent network operating system.

A few months ago I met a number of great engineers from Avaya and they explained to me how they creatively use Shortest Path Bridging (SPB) to create layer-2, layer-3, L2VPN, L3VPN and even IP Multicast fabrics – it was clearly time for another deep dive into SPB.

It took me a while to meet again with Roger Lapuh, but finally we started exploring the intricacies of SPB, and even compared it to MPLS for engineers more familiar with MPLS/VPN. Interested? Listen to Episode 54 of Software Gone Wild.

Continuing our routing-on-hosts discussions, Enno Rey (of the Troopers and IPv6 security fame) made another interesting remark “years ago we were so happy when we finally got rid of gated on Solaris” and I countered with “there are still people who fondly remember the days of running gated on Solaris” because it’s a nice solution to host-to-network multihoming problem.

After I told you that I’m not going to Interop, I got numerous emails along the lines of “but I was really looking forward to attending your workshop” so I started looking for a solution that would combine the best of online and classroom worlds.

Here’s my first attempt: an interactive online course combining topics from two of my Interop workshops. I’m still working on the detailed agenda and plan to have it ready around May 1st. In the meantime, I’d really appreciate your feedback – leave a comment or send me an email.