Current Trends in DC Networking - Cumulus Config w/ Ansible Roles

This post will finish up the networking side of this series. Up till now we have learned about VxLAN and deploying it in both Arista and Cumulus spine/leaf fabrics. We also learned how to automate the creation of configuration files and how to deploy them onto Arista gear using Ansible and NAPALM.

Next we need to expand the Ansible playbooks we have created to include the configuration of Cumulus switches. I will also take this opportunity to cover Ansible roles.

I was hoping to cover the Cumulus Ansible module for this post, but at the time of this writing (April 2017) the current version does not support VxLAN configuration. So we will have to just work with static files.

So lets get started!


Current Trends in DC Networking - Arista Ansible Config

Over the past few post I have covered the basics of Ansible, now its time to dig in and see how we can leverage it to build configurations. The cool thing about Ansible is there is a number of ways to accomplish most task. From here on out, it’s honestly about exploring what options are available within Ansible and expanding skills as you learn.

This post we will focus on configuring the Arista fabric from scratch using the configurations we have developed over the series. Configuration can be approach two ways.
  1. Push configuration to each switch with Ansible modules or roles directly.
  2. Build the configurations in full, then push them to each switch.

Both options have their place. The first might be a good fit for interacting directly with a large group of production switches to make smaller changes. The second would be good for pre-building configuration for groups of devices and pushing once they are installed. It would also be a good way to integrate with an existing configuration management tool or get one started.

This post we will focus on the second options, mostly because it can be used for any vendor, not just Arista. And Im sure just like me most of us still have some Cisco or Juniper gear sitting around in our DCs so we can still benefit from this exercise.

Alright,  lets dig in!


Current Trends in DC Networking - Ansible Basics

In the last post we covered the install and a quick introduction to Ansible. Today I will go over the basics of Ansible and how to build and run playbooks.

Ansible is very powerful and flexible. Configuration and usage gets deep quick. The best way I have learned to dig in, is to start simple and build from there. So that is what we will do today, build a basic playbook and run some commands on our remote switches.


Current Trends in DC Networking - Ansible

Moving along in the series, I guess its time to start automating something, right? Yes lets automate!

Ansible has been around for a while and is popular among server and network engineers. As the product matures the community backing and support keeps growing and getting stronger.

On the server side of the house, Ansible is great at automating the build and deployment of service stacks on hardware, VMs or in the cloud. This is were Ansible started and is the strongest in my opinion. On the network side, Ansible is still growing and has some challenges with managing network devices. I dont blame Ansible for this, but blame the vendors for the outdated means of communication with their equipment. This is changing but its going to take time.

With that being said, Ansible is still a great tool to automate the configuration and deployment of network equipment.

Over the next few post I am going to cover the basics of Ansible and then walk through building out both the Arista and Cumulus networks we just built up.

So lets get started!


Current Trends in DC Networking - Cumulus EVPN VXLAN

In my previous post on Cumulus Networks we covered the basics and getting BGP peering setup with our data center (DC) topology. Now we need to get VxLAN working to move forward with our design.

Cumulus has had a VXLAN solution called LNV (Lightweight Network Virtualization) for a while. But with version 3.2 of Cumulus linux we now have the option to use an EVPN control plane. I spoke briefly about EVPN in my Introduction to VxLAN post and it appears the market is shifting to EVPN control plan as the popular VxLAN solution. Cisco and Juniper both support EVPN and Arista will hopefully release their version sometime early 2017.

Ive never been a big fan of EVPN as the VxLAN control plane, mostly due to its complexity, but EVPN has a lot of potential behind it that could introduce some cool features in the future.

So lets dig in.


New Year, New Focus

2016 has been a busy year. Both career and family have demanded a ton of my time leaving very little for myself, this blog and social media. The CCIE took a huge toll on my family, and they deserved me back for at least a couple months!

2016 was the first year in my career I was free from the rat race of certification/education and more recently the CCIE. My intent for the year was to focus my time and efforts on new and emerging technologies in the data center space. I started my current blog series Current Trend in DC Networking way too long ago and have slowly been moving my way through as a way to dig into these technologies. I have not given this series the time it deserves, but I plan to pick up the pace moving forward..

This coming year, I plan to spending more time in the lab, blogging and social media in general.


Current Trends in DC Networking - Cumulus Networks

Hopefully by now you have heard about Cumulus Networks. If not here is a quick intro.

Cumulus Networks is a full feature Linux distribution for data center (DC) routers and switches. Cumulus Linux is designed to simplify the deployment and automation of DC networks. With that said its not your normal network OS. The configuration and management is more inline with a Debian server than a network switch.

So what? Why change what has been working for several decades?

That is the point. What has worked for us in the past is not holding up to the rapidly changing DC space. Technologies are integrating, workflows are merging and yet we still grind away at notepad just to copy/paste into the CLI when new switches need deployed or VLANs need provisioned. Why?

Cumulus Networks is trying to lead the charge in changing this. By building a network OS that can better integrate with the tools already proven by application and server teams, we can quickly deploy and automate the network infrastructure with ease.

For a deeper introduction into Cumulus Networks check out the awesome Tech Field Day videos from #NFD9.