Alex was trying to figure out how to use Catalyst 3850 switches and sent me this question:

Is MLAG an alternative to use rather than physically creating a switch stack?

Let’s start with some terminology.

Link Aggregation Group (LAG) is the ability to bond multiple Ethernet links into a single virtual link. LAG (as defined in 802.1ax standard) can be used between a pair of adjacent nodes. While that’s good enough if you need more bandwidth it doesn’t help if you want to increase redundancy of your solution by connecting your edge device to two switches while using all uplinks and avoiding the shortcomings of STP. Sounds a bit like trying to keep the cake while eating it.

When VMware launched the first version of NSX for vSphere more than four years ago, the NSBU team reached out to me and asked me to create a sponsored webinar describing NSX fundamentals, its architecture, and high-level deployment guidelines.

In the meantime we discussed updating the materials, but nothing ever happened. Time to fix that, this time from a vendor-neutral perspective. We’ll start with a day-long event on April 19^th 2018 in Zurich, Switzerland.

I asked David Gee to review my streaming telemetry blog posts to make sure I didn’t make too many blunders, and he sent me a nice summary of his view on the topic in return.

The only thing I could do after reading it was to ask him for permission to do a copy-paste. Here it is:

One of the biggest challenges of network automation is getting usable information from network devices… or as asked by a student in my Building Network Automation Solutions online course in the course Slack team:

How do I get specific information from a specific command from a device without an Ansible Network Module? Is Python the only suggested approach?

I described how hard it is to get structured information from network devices in great details in this section of the Ansible for Networking Engineers webinar and online course. Here are a few more thoughts on the topic:

Someone pointed me to this article by dr. Paul Vixie (of the DNS fame). The best part (as I’m not a security person):

The TCO of new technology products and services, including security-related products and services, should be fudge-factored by at least 3X to account for the cost of reduced understanding. That extra 2X is a source of new spending: on training, on auditing, on staff growth and retention, on in-house integration.

In case you didn’t get it: figure out how much you think the magic unicorn-based software-defined solution will cost, then multiply it by three. Of course nobody wants to admit that.

I was focused on network automation this week, starting with a 2-day workshop and continuing with an overview of real-life automation wins. Let’s end the week with another automation story: automated data center fabric deployment demonstrated by Dinesh Dutt during his part of Network Automation Use Cases webinar.

You’ll need at least free ipSpace.net subscription to watch the video.

We managed to get another awesome lineup of speakers for the Spring 2018 Building Next-Generation Data Center online course.

Russ White, one of the authors of CCDE and CCAr programs and highly respected book author will start the course with a topic everyone should always consider when designing new infrastructure: how do you identify tradeoffs and manage complexity, making sure you meet the customer requirements while at the same time having an easy-to-operate infrastructure.

One of my readers sent me a question along these lines after reading the anti-automation blog post:

Your blog post has me worried as we're currently reviewing offers for NGFW solution... I understand the need to keep the lid on the details rather than name and shame, but is it possible to get the details off the record?

I always believed in giving my readers enough information to solve their challenges on their own (you know, the Teach a man to fish idea).

Continuing the Streaming Telemetry saga, let’s focus on presentation formats and transport mechanisms.

I already mentioned three presentation formats: XML (used by NETCONF), JSON (used by RESTCONF) and Protocol Buffers (used by gRPC). Two of them are text-based, the third one (Protocol Buffers) is binary encoding not unlike ASN.1 BER used by SNMP. That can’t be good in a JSON-hyped world, right?

One of the most important aspects of the introductory part of my Building Network Automation Solutions online course is the question should I buy a solution or build my own?

I already described the arguments against buying a reassuringly-expensive single-blob-of-complexity solution from a $vendor, but what about using point tools?