Category: automation

I got interesting feedback from one of my readers after publishing my REST API Is Not Transactional blog post:

One would think a transactional REST interface wouldn’t be too difficult to implement. Using HTTP1/1, it is possible to multiplex several REST calls into one connection to a specific server. The first call then is a request for start a transaction, returning a transaction ID, to be used in subsequent calls. Since we’re not primarily interested in the massive scalability of stateless REST calls, all the REST calls will be handled by the same frontend. Obviously the last call would be a commit.

I wouldn’t count on HTTP pipelining to keep all requests in one HTTP session (mixing too many layers in a stack never ends well) but we wouldn’t need it anyway the moment we’d have a transaction ID which would be identical to session ID (or session cookie) traditional web apps use.

TL&DR: You automate the whole process. What else do you expect?

During the Tech Field Day Extra @ Cisco Live Europe 2019 we were taken on a behind-the-stage tour that included a chat with people who built the Cisco Live network, and of course I had to ask how they automated the whole thing. They said “well, we have the guy that wrote the whole system onsite and he’ll be able to tell you more”. Turns out the guy was my good friend Andrew Yourtchenko who graciously showed the system they built and explained the behind-the-scenes details.

How nice would it be to have a fabric health dashboard displaying a summary of numerous parameters you’re interested in (number of operational uplinks, number of BGP sessions…) for every switch in your fabric.

I’m positive you could hack something together using the customization capabilities of your favorite network management system… or you could write a simple data gathering solution like Stephen Harding did while attending the Building Network Automation Solutions online course.

Have you ever seen an Ansible playbook where 90% of the code prepares the environment, and then all the work is done in a few template and assemble modules? Here’s an alternative way of getting that done. Is it better? You tell me ;)

Remember Nicky Davey describing how he got large DMVPN deployment back on track with configuration templating? In his own words…:

Configuration templating is still as big win a win for us as it was a year ago. We have since expanded the automation solution, and reading the old blog post makes me realise how far we have come. I began working with this particular customer in May 2017, so 2 years now. At that time the new WAN project was on the horizon and the approach to network configuration was entirely manual.

Here’s how far he got in the meantime:

Last week I covered network security groups, application security groups and user-defined routes in the second live session of Azure Networking webinar.

We also had a great guest speaker on the Network Automation course: Damien Garros explained how he used central source-of-truth based on NetBox and Git to set up a network automation stack from the grounds up.

Recordings are already online; you’ll need Standard ipSpace.net Subscription to access the Azure Networking webinar, and Expert ipSpace.net Subscription to access Damien’s presentation. Azure Networking webinar is also part of our new Networking in Public Clouds online course.

A while ago Ruben Tripiana tried to configure BGP on Cisco IOS using IETF YANG data models… and failed. In Spring 2019 Building Network Automation Solutions online course Chris Crook decided to deploy BGP routing on multiple platforms using YANG data models instead of configuration templates. Not only did he succeed, he also documented his work and the tools he used, and published the solution so you can replicate his efforts.

You can find many more network automation solutions created by the attendees of our automation course in solutions showcase.

I had a fantastic chat with David Bombal a while ago in which we covered tons of network automation topics including “should I use Nornir or NAPALM or Netmiko?”

The only answer one can give would be “it depends… on what you’re trying to do” as these three tools solve completely different challenges.

Paramiko is SSH implementation in Python. It’s used by most Python tools that want to use SSH to connect to other hosts (including networking devices).

Someone working for a network automation startup desperately tried to persuade me how cool their product is. Here’s what he sent me:

We let network engineers build their own network automation solutions in no time without requiring coding or scripting knowledge. It’s all GUI based, specifically geared towards network engineers - they can simply model services or roll-out networks “as-designed”.

The only problem: I’ve seen that same argument numerous times…

Last week we started the Autumn 2019 Building Network Automation Solutions online course with an interesting presentation from Matthias Luft focused on open-source supply chain security

TL&DR: Can I download whatever stuff I found as my first Google hit and use it in my automation solution? ****, NO!

Matthias covered these topics:

This blog post was initially sent to subscribers of my SDN and Network Automation mailing list. Subscribe here.

Have you ever seen a presentation in which a startup is telling you how awesome their product is because it allows you to simulate your whole network in a virtual environment? Not only that, you can use that capability to build a test suite and a full-blown CI/CD pipeline and test whether your network works every time you make a change to any one box in the network.

Sounds awesome, right? It’s also dead wrong. Let me explain why that’s the case.

Andrea Dainese decided to describe a series of mechanisms and protocols you can use in network automation. He started with Zero-Touch Provisioning and continued with screen scraping. Next one on his list: NETCONF and RESTCONF

I was saying “you’ll get the best network automation (or SDN) results if you pair network engineers with software engineers” for ages, but there’s always someone else saying it more eloquently, in this case Jeremy Schulman in his recent blog post.

Jeremy will talk about ChatOps in Autumn 2019 Building Network Automation Solutions online course, but of course you’re more than welcome to ask him other questions as well.

Daniel Teycheney attended the Spring 2019 Building Network Automation Solutions online course and sent me this feedback after completing it (and creating some interesting real-life solutions on the way):

I spent a bit of time the other day reflecting on how much I’ve learn’t from the course in terms of technical skills and the amount I’ve learned has been great. I literally no idea about things like Git, Jinja2, CI testing, reading YAML files and had only briefly seen Ansible before.

I’m not an expert now, but I understand these things and have real practical experience on these subjects which has given me great confidence to push on and keep getting better.

When I was still at university the fourth-generation programming languages were all the hype, prompting us to make jokes along the lines “fifth generation will implement do what I don’t know how”

The research team working in Networked Systems Group at ETH Zurich headed by prof. Laurent Vanbever got pretty close. The description of their tool says: