Some of the things Ethan Banks writes are epic. The latest one I stumbled upon: Things Network Engineers Hate. I particularly loved the rant against long-distance vMotion (no surprise there ;).

One of the design scenarios we covered in Leaf-and-Spine Fabric Architectures webinar is a pure layer-3 data center, and in the “how do I do this” part of that section Dinesh Dutt talked about the details you need to know to get this idea implemented on Cumulus Linux.

We covered a half-dozen design scenarios in that webinar; for an even wider picture check out the new Designing and Building Data Center Fabrics online course.

In one of the previous blog posts I described the playbook I use to collect SSH keys from network devices. As I use it quite often, it became tedious to write ansible-playbook path-to-playbook every time I wanted to run the collection process.

Ansible playbooks are YAML documents, and YAML documents use # to start comments, so I thought “what if I’d use a YAML comment to add shebang and turn my YAML document into a script”

TL&DR: It works. Now for the longer story…

Second vendor in this year’s series of data center switching updates: Brocade.

Not much has happened on this front since last year’s update. There was a maintenance release of Brocade NOS, they launched SLX series of switches, but those are so new that the software documentation didn’t have time to make it to the usual place (document library for individual switch models), it's here.

In any case, the updated videos (including edited 2016 content which describes IP Fabric in great details) are online. You can access them if you bought the webinar recording in the past or if you have an active ipSpace.net subscription.

In case you’re not familiar with RFC 1925, Rule 5 states:

It is always possible to agglutinate multiple separate problems into a single complex interdependent solution. In most cases, this is a bad idea.

Most routing protocols are a perfect demonstration of this rule.

Sometimes I have this weird feeling that I’m the only loony in town desperately preaching against the stupidities heaped upon infrastructure, so it’s really nice when I find a fellow lost soul. This is what another senior networking engineer sent me:

I'm belonging to a small group of people who are thinking that the source of the problem are the apps and the associated business/security rules: their nature, their complexity, their lifecycle...

Sounds familiar (I probably wrote a few blog posts on this topic in the past), and it only got better.

Gian Paolo Boarina published a great article following my Are You Solving the Right Problem rant.

Long story short: everyone in the networking game has their own agenda, and it’s not necessarily good for you or your business.

In June 2017, we concluded the Building Next Generation Data Center online course with a roundtable discussion with Andrew Lerner, Research Vice President, Networking, and Simon Richard, Research Director, Data Center Networking @ Gartner.

In the second half of our discussion (first half is here) we focused on these topics:

In the past 5+ years I ran at least one Data Center Fabrics Update webinar per year to cover new hardware and software launched by data center switching vendors.

The rate of product and feature launches in data center switching market is slowing down, so I decided to insert the information on new hardware and software features launched in 2017 directly into the merged videos describing the progress various vendors made in the last years.

First in line: Arista EOS. You can access the videos if you bought the webinar recording in the past or if you have an active ipSpace.net subscription.

One of my friends sent me this design challenge:

Assume you’re migrating from another WAN transport technology to MPLS. The existing network has 3000 routes but the MPLS carrier is limiting you to 1000 routes. How could you solve this with MPLS?

Personally, I think MPLS is a red herring.

With all the intent-based hype (and the previous SDN-will-rule-the-world-hype) you’d think that the network is the ultimate ossified roadblock on the path to agile nirvana.

You’d be totally wrong (and you’d deserve it – never trust a vendor peddling a product).

Here’s an amazing discovery I made when I was still running on-site SDN and network automation workshops.

Here’s the list of webinars and events planned for October and November 2017:

• Second part of Network Visibility with Flow Data webinar on October 5th;
• Network automation workshop in Rome on October 18th;
• Cumulus Linux Update (part of Data Center Fabrics updates) on October 26th;
• QoS webinar on November 9th (no description yet);
• Day-long data center automation event in Zurich on November 14th (more details soon).

Hint: you get access to all live webinar sessions, and 170 hours of downloadable videos with ipSpace.net subscription.

An update of PERL libraries broke a number of my scripts (don't ask). Here's the current status:

• Fixed: credit card processing. It was impossible to buy products from ipSpace.net with credit cards (the credit card form didn't appear at all)
• Fixed: Google+ login
• Unrelated and fixed: blog search

Anything else not working? Please write a comment or send me an email. Thank you!

A while ago a large airline had a bad-hair day claiming it was caused by a faulty power supply. Not surprisingly, I got a question along the lines of “is that feasible?”

Short answer: Yes. However, someone should be really worried if that wasn’t made up.

Here’s a common scenario I’m encountering on Ansible-related forums:

Q: I cannot connect to network devices with my Ansible network modules. I keep getting these weird error messages…

Me: Are you sure you have the device SSH keys in known_hosts file?

Q: How did you know?