Network architecture for large scale MAAS deployment

Hey there!

Recently I came across MAAS and I tried it in combination with juju and it’s great! So easy to manage and automate things, ridiculous! But now I’m wondering how an appropriate network topology for large scale deployments would look like?

Let’s imagine you’ve got the following scenario, that should be handled by using MAAS:

  • building a private cloud
  • 500 server racks
  • 40 machines each
  • each rack has it’s dedicated rack controller and ToR-switch(es)

First I started using a network to get all those addresses fitting and have some scale options for future needs. But in a different discussion, I noticed using such a big network gets inperformant very quickly. For those purpose, each rack should have its own dedicated subnet, let’s say,, and so on, which can be interconnected defining a space.

What I do not understand is, in which network are all those rack controllers placed? Within each subnet or the underlying network? Another question arised: how to adjust those architecture to fit more racks let’s say 1000 and more into the same maas deployment? Using a /24 CIDR in combination with a 10.x.x.x address space would allow 254 * 2 subnets, wouldn’t it?

Many thanks in advice, feel free to ask questions if something Isn’t understandable :slight_smile:

@andreasteich97, first, let me confirm a couple of things: you are talking about a private cloud with 20,000 machines and 500 MAAS rack controllers, correct? how many machines active at once?

At least, yes! So of that‘s realistic or not, in the best case all 20.000 machines! :grinning_face_with_smiling_eyes:

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that’s good, glad to understand it.

wrt your networking question, quite honestly, it’s somewhat dependent on good networking design. you mention in your other post that you are somewhat new to larger networks, or did i misunderstand that?

Yes that‘s correct as well!

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cool. okay, there is some network planning that is independent of MAAS. my advice would be to google for “network planning” “network sizing” “subnet sizing” “network design” and look for the better tutorials. if you get totally stuck, let me know.

Thanks for your time and thoughts. I already did that many times, but got to the point where transfering this theoretical knowledge to production using maas is quite hard for me. Let‘s say you have the following circumstances:

  • one network to use for the maas env (like Region Controller and I guess the Single rack controllers)
  • each rack controller gets a dedicated subnet for it‘s machines

Yes I‘m aware of the fact that the maas Network in theory is just capable of round about 250 rack controllers, if they get Placed within this Network. Is it best practice to setup a maas deployment for larger scale like That or isn‘t it? :slightly_frowning_face:

Hi Andreas, interesting to read your questions. I’m curious to learn more about your use case, and how you have gotten on with using MAAS.

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