We started March 2020 with the second part of Cisco SD-WAN webinar by David Peñaloza Seijas, continued with Upcoming Internet Challenges update, and concluded with 400 GE presentation by Lukas Krattiger and Mark Nowell.

You can access all these webinars with Standard or Expert ipSpace.net subscription. The Cisco SD-WAN presentation is already available with free ipSpace.net subscription, which will also include the edited 400 GE videos once we get them back from our video editor.

Git is great (once you get beyond the basic recipes), and I love my new blog setup that allows me to keep track of all the changes I make with Git.

However, there’s a slight gotcha if you use Git with Markdown: whenever you change something, the whole line (and using tools like IA Writer a whole paragraph is a single line) is marked as changed, for example:

Adrian Giacometti described how he used Elastic Stack (ELK) to build a dashboard for his integration tests and network logs.

Maybe it’s time to build our own network monitoring systems from open-source components instead of paying vendors big bucks for slick PowerPoint slides.

David Penaloza decided to demystify Cisco’s SD-WAN, provide real world experience beyond marketing hype, and clear confusing and foggy messages around what can or cannot be done with Cisco SD-WAN.

He started the first part of his Cisco SD-WAN Foundations and Design Aspects webinar with a quick look beneath the surface of shiny marketing and corporate slidess.

One of the attendees of my Building Network Automation Solutions online course quickly realized a limitation of Ansible (by far the most popular network automation tool): it stores all the information in random text files. Here’s what he wrote:

I’ve been playing around with Ansible a lot, and I figure that keeping random YAML files lying around to store information about routers and switches is not very uh, scalable. What’s everyone’s favorite way to store all the things?

He’s definitely right (and we spent a whole session in the network automation course discussing that).

Let’s agree for a millisecond that you can’t find any other way to migrate your workload into a public cloud than to move the existing VMs one-by-one without renumbering them. Doing a clumsy cloud migration like this will get you the headaches and the cloud bill you deserve, but that’s a different story. Today we’ll talk about being clumsy the right and the wrong way.

There are two ways of solving today’s challenge:

Jeff Tantsura published a great response to my Can We Trust BGP Next Hops blog post on LinkedIn, and I asked him for permission to save it in a more permanent form. Here it is (slightly edited)…

I’d like to bring back EVPN context. The discussion is more nuanced, the common non-arguable logic here - reachability != functionality.

Numerous online companies are using the COVID-19 crisis to make their products better known (PacketPushers collected some of them). Nothing wrong with that - they’re investing into providing free- or at-cost resources, and hope to get increased traction in the market. Pretty fair and useful.

Then there are others… Here’s a recent email I got:

Way too many people still believe in Security Fairy (the mythical entity that makes your application magically secure), fueling the whole industry of security researchers who happily create excruciatingly detailed talks of how you can use whatever security oversight to wreak havoc (even when the limitations of a technology are clearly spelled out in an RFC).

In the Networks Are Not Secure (part of How Networks Really Work webinar) I described why we should never rely on the network infrastructure to provide security but have to implement it higher up in the application stack.

Andrea Dainese added REST (Web) API to his Automation for Cisco NetDevOps article. You might love his explanation of the screen scraping methods used by legacy implementations. He was too polite to throw around any names, but I could immediately think of NETCONF or RESTCONF implementation on Cisco IOS.

One of our subscribers sent me this email when trying to use ideas from Ansible for Networking Engineers webinar to build BGP route reflector configuration:

I’m currently discovering Ansible/Jinja2 and trying to create BGP route reflector configuration from Jinja2 template using Ansible playbook. As part of group_vars YAML file, I wish to list all route reflector clients IP address. When I have 50+ neighbors, the YAML file gets quite unreadable and it’s hard to see data model anymore.

Whenever you hit a roadblock like this one, you should start with the bigger picture and maybe redefine the problem.

Aldrin sent me an interesting question as a comment to one of my EVPN blog posts:

How does the network know that a VTEP is actually alive? (1) from the point of view of the control plane and (2) from the point of view of the data plane? And how do you ensure that control and data plane liveness monitoring has the same view? BFD for BGP is a possible solution for (1) but it’s not meant for 3rd party next hops, i.e. it doesn’t address (2).

Let’s stop right there (or you’ll stop reading in the next 10 milliseconds). I will also try to rephrase the question in more generic terms, hoping Aldrin won’t mind a slight detour… we’ll get back to the original question in another blog post.

Over the last weekend I almost got pulled into yet-another CLI-or-automation Twitter spat. The really sad part: I thought we were past that point. After all, I’ve been ranting about that topic for almost seven years… and yet I’m still hearing the same arguments I did in those days.

Just for the giggles I collected a few old blog posts on the topic (not that anyone evangelizing their opinions on Twitter would ever take the time to read them ;).

Most of us are in some sort of lockdown (or quarantine or shelter-in-place or whatever it’s called) at the moment. Some have their hands full balancing work and homeschooling their kids (hang in there!), others are getting bored and looking for networking-related content (or you wouldn’t be reading this blog).

If you’re in the latter category you might want to browse some of the free ipSpace.net content: almost 3500 blog posts, dozens of articles, over a hundred podcast episodes, over 20 free webinars, and another 30+ webinars with sample videos that you can access with free subscription.

Need more? Standard subscription includes 260 hours of video content and if you go for Expert subscription and select the network automation course as part of the subscription, you’ll get another 60 hours of content plus hands-on exercises, support, access to Slack team… hopefully enough to last you way past the peak of the current pandemic.

As I explained in How Networks Really Work and Upcoming Internet Challenges webinars, routing security, and BGP security in particular remain one of the unsolved challenges we’ve been facing for decades (see also: what makes BGP a hot mess).

Fortunately, due to enormous efforts of a few persistent individuals BGP RPKI is getting traction (NTT just went all-in), and Flavio Luciani and Tiziano Tofoni decided to do their part creating an excellent in-depth document describing BGP RPKI theory and configuration on Cisco- and Juniper routers.

There are only two things you have to do:

• Read the document;
• Implement RPKI in your network.

Thank you, the Internet will be grateful.