One of the undergraduate students attending my Ansible for Networking Engineers online course got to the point where he wanted to start hands-on work and sent me a list of questions:

Do I have to buy a VIRL license to use your Ansible course materials? Or is VIRL in any Github repository? Is there a way to use your files in a free Tool like GNS3?

Let’s go through them one by one:

During Cisco Live Berlin 2017 Peter Jones (chair of several IEEE task forces) and myself went on a journey through 40 years of Ethernet history (and Token Bus and a few other choice technologies).

The sound quality is what you could expect from something recorded on a show floor with pigeons flying around, but I hope you’ll still enjoy our chat.

One of the sample Ansible playbooks I published to help the attendees of my Building Network Automation Solutions course get started collects LLDP neighbor information on all managed devices and converts that information into a network diagram.

Here’s the graph I got from it when I ran it on my 6-node OSPF network (the Inter-AS VIRL topology from this repository). Please note I spent zero time tweaking the graph description (it shows).

Some engineers solving the original challenges Johannes posted complained that they were too easy, so he created another scenario: find out what’s wrong in an IPsec setup using just the captured traffic. Good luck!

Got this comment on one of my blog posts:

When looking at some of the CLIs just front-ending RESTAPIs, I wonder if "survival" of CLI isn't just in the eyes of the beholder.

It made me really sad because I wrote about this exact topic several times… obviously in vain. Or as one of my network automation friends said when I asked him to look at the draft of this blog post:

Omer asked a pretty common question about BFD on one of my blog posts (slightly reworded):

Would you still use BFD even if you have a direct router-to-router physical link without L2 transport in the middle to detect if there is some kind of software failure on the other side?

Sander Steffann quickly replied:

Validating the expected network behavior is (according to the intent-driven pundits) a fundamental difference that makes intent-driven products more than glorified orchestration systems.

Guess what: smart people knew that for ages and validated their deployments even when using simple tools like Ansible playbooks.

Dinesh Dutt explained how he validates data center fabric deployment during the Network Automation Use Cases webinar; I’m doing something similar in my OSPF deployment playbooks (described in detail in Ansible online course).

One of my readers sent me an interesting DMVPN routing question. He has a design with a single DMVPN tunnel with two hubs (a primary and a backup hub), running BGP between hubs and spokes and IBGP session between hubs over a dedicated inter-hub link (he doesn’t want the hub-to-hub traffic to go over DMVPN).

Here's (approximately) what he's trying to do:

David Gee (whom I finally met in person during recent ipSpace.net Summit) published a fantastic series of articles on what someone bringing together networking, development and automation should know and do.

In every SDDC workshop I tried to persuade the audience that the virtual appliances (particularly per-application instances of virtual appliances) are the way to go. I usually got the questions along the lines of “who will manage and audit all these instances?” but once someone asked “and how will we upgrade them?”

Short answer: you won’t.