Layers of Single-Pane-of-Glass Abstractions Won’t Solve Your Problems

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We’ve been told for years how we’re over-complicating networking, and how the software-defined or intent-based whatever will remove all that complexity and remove the need for networking engineers.

What never ceases to amaze me is how all these software-defined systems are demonstrated: each one has a fancy GUI that looks great in PowerPoint and might even work in practice assuming you’re doing exactly what they demonstrated… trying to be creative could result in interesting disasters.

Autumn 2018 Network Automation Course Starts on September 18th

When the Spring 2018 Building Network Automation Solutions online course started, we didn’t know whether we’d run another course in 2018, so we offered engineers who wanted to get an early start Believer price.

The wait is over: the autumn 2018 course starts on September 18^th. The schedule of the live sessions is already online, and we also have the first guest speakers. We’ll announce them in early June at which time you will no longer be able to get the Enthusiast price, so register ASAP.

The Difference between Hodgepodge PoC and Production

A friend of mine who had the unfortunate “pleasure” of being exposed to one of the open-source controller platforms sent me this after reading my snarky take on bragging about what you’re doing at Something-Open-Something-Something conferences.

Using 4-Byte BGP AS Numbers with EVPN on Junos

After documenting the basic challenges of using EBGP and 4-byte AS numbers with EVPN automatic route targets, I asked my friends working for various vendors how their implementation solves these challenges. This is what Krzysztof Szarkowicz sent me on specifics of Junos implementation:

To learn more about EVPN technology and its use in data center fabrics, watch the EVPN Technical Deep Dive webinar.

Network Automation with Brigade on Software Gone Wild

David Barroso was sick-and-tired of using ZX Spectrum of Network Automation and decided to create an alternative with similar functionality but a proper programming language instead of YAML dictionaries masquerading as one. The result: Brigade, an interesting network automation tool we discussed in Episode 90 of Software Gone Wild.

Notes:

• If you want to test-drive Brigade, start here;
• To get the references at the end of our chat, watch this and this;
• David will talk about Brigade in autumn 2018 session of Building Network Automation Solutions online course.

Automation Win: Zero-Touch Provisioning

Listening to the networking vendors it seems that zero-touch provisioning is a no-brainer … until you try to get it working in real life, and the device you want to auto-configure supports only IP address assignment via DHCP, configuration download via TFTP, and a DHCP option that points to the configuration file.

As Hans Verkerk discovered when he tried to implement zero-touch provisioning with Ansible while attending the Building Network Automation Solutions course you have to:

Update: Automatic EVPN Route Targets in EBGP Environments

After I posted the EVPN Route Target Considerations section of BGP in Data Center Fabrics document Lukas Krattiger pointed out another option available with Cisco Nexus-OS: it can rewrite ASN portion of EVPN Route Target in incoming EBGP updates. Updated version of the affected section is already online.

We Have to Learn How to Manage the Cattle

Not long after I published the blog post arguing against physical appliances, Oven wrote a very valid comment: "But then you'd have 20 individual systems to manage, add licenses to for additional features, updates etc."

Even though the blog post (and the comment) was written in 2013, not much has changed in the meantime.

Avoid Write-Only Code

You probably know that fantastic feeling when you think your newly-discovered tool is a Hammer of Thor, capable of solving every problem (or at least crashing through it). I guess you’re also familiar with that sinking feeling when you’re trying to use your beloved hammer to whitewash a bikeshed.

Not surprisingly, the cruder the tool is, the quicker you’ll hit its limits, like when you try to do data processing in Jinja2 (hint: don’t).

Is OSPF Unpredictable or Just Unexpected?

I was listening to very interesting Future of Networking with Fred Baker a long while ago and enjoyed Fred’s perspectives and historical insight, until unfortunately Greg Ferro couldn’t possibly resist the usual bashing of traditional routing protocols and praising of intent-based (or flow-based or SDN or…) whatever.

Here’s what I understood he said around 35:17

Podcast: Automation, Intent-Based Systems and Everything Else

A while ago Greg Ferro invited me for another fireside chat on Packet Pushers podcast. Hope you’ll enjoy our discussion.

Configuration Templating Could Be a Huge Win

The network automation evangelists love to tell you that automation is more than just device configuration management. They’re absolutely right… but it’s nonetheless amazing how much good you could do with simple tools solving simple problems.

Here’s what I got from Nicky Davey:

Upcoming Webinars: May and June 2018

Another month has swooshed by and it’s time for a refreshed list of upcoming webinars:

• Mitja Robas will explain the basics of NSX and ACI planning and design on April 24th. He has tons of material on this topic – expect to see him quite often in the autumn/winter timeframe;
• Dinesh Dutt will continue the EVPN Technical Deep Dive saga on May 3^rd;
• Christoph Jaggi will run a free webinar on the basics of transport (layer-1/2) and network (layer-3) security on May 10^th;
• We’ll run another SDDC webinar on May 22^nd. More details later…
• On June 5^th Christoph will be back with Ethernet Encryptors Deep Dive;
• The last webinar before the summer break will be Data Center Fabric Troubleshooting with Dinesh Dutt on June 19^th.

All you need to have to attend all these live sessions is a current ipSpace.net webinar subscription.

What Came First: VLANs or VRFs?

One of my friends sent me this question:

Do you remember if VLANs came first or was it VRFs?

I remember VLANs using ISL (pre-802.1q encapsulation) on early Cisco Ethernet switches (mid 90s), the earliest reference I could track down on Wikipedia is from 1988.

Found on the Web: Your CLI Should Be a Server

Guess what I found: a software developer trying to persuade his peers that they need an API version of their CLI tool. Yes, I checked and it’s still 2018, and the year CLI dies seems to be a bit further out than some people thought.

I’d guess this proves that the rest of the world is not so far ahead of us lowly network engineers as blabbering pundits and vendor marketers would have us believe.

Needless to say, the engineers architecting Junos knew this almost 20 years ago.

OpenFabric with Russ White on Software Gone Wild

Continuing the series of data center routing protocol podcasts, we sat down with Russ White (of the CCDE fame), author of another proposal: OpenFabric.

As always, we started with the “what’s wrong with what we have right now, like using BGP as a better IGP” question, resulting in “BGP is becoming the trash can of the Internet”.

Why Can’t We All Use Provider-Independent IPv6 Addresses?

Here’s another back-to-the-fundamentals question I received a while ago when discussing IPv6 multihoming challenges:

I was wondering why enterprise can’t have dedicated block of IPv6 address and ISPs route the traffic to it. Enterprise shall select the ISP's based on the routing and preferences configured?

Let’s try to analyze where the problem might be. First the no-brainers:

Pragmatic Data Center Fabrics

I always love to read the practical advice by Andrew Lerner. Here’s another gem that matches what Brad Hedlund, Dinesh Dutt and myself (plus numerous others) have been saying for ages:

One specific recommendation we make in the research is to “Build a rightsized physical infrastructure by using a leaf/spine design with fixed-form factor switches and 25/100G capable interfaces (that are reverse-compatible with 10G).”

There’s a slight gotcha in that advice: it trades implicit complexity of chassis switches with explicit complexity of fixed-form switches.

Interview: Programmable Infrastructure Is Just a Tool

A while ago I did an interview about programmable infrastructure that got published as an article in mid-March. As you might expect, my main message was “technology will never save you unless you change your processes to adapt to its benefits.”

Hope you’ll enjoy it!

Should I Take CCIE DC or ipSpace.net Data Center Online Course?

Got this question from a networking engineer who couldn’t decide whether to go for CCIE Data Center certification or attend my Building Next-Generation Data Center online course:

I am considering pursuing CCIE DC. I found your Next-Generation DC course very interesting. Now I am bit confused trying to decide whether to start with CCIE DC first and then do your course.

You might be in a similar position, so here’s what I told him.