Is ACI Coming For The CLI?


I’m soon to depart from Cisco Live Barcelona. It’s been a long week of fun presentations. While I’m going to avoid using the words intent and context in this post, there is one thing I saw repeatedly that grabbed my attention. ACI is eating Cisco’s world. And it’s coming for something else very soon.

Devourer Of Interfaces

Application-Centric Infrastructure has been out for a while and it’s meeting with relative success in the data center. It’s going up against VMware NSX and winning in a fair number of deals. For every person that I talk to that can’t stand it I hear from someone gushing about it. ACI is making headway as the tip of the spear when it comes to Cisco’s software-based networking architecture.

Don’t believe me? Check out some of the sessions from Cisco Live this year. Especially the Software-Defined Access and DNA Assurance ones. You’re going to hear context and intent a lot, as those are the key words for this new strategy. You know what else you’re going to hear a lot?

Contract. Endpoint Group (EPG). Policy.

If you’re familiar with ACI, you know what those words mean. You see the parallels between the data center and the push in the campus to embrace SD-Access. If you know how to create a contract for an EPG in ACI, then doing it in DNA Center is just as easy.

If you’ve never learned ACI before, you can dive right in with new DNA Center training and get started. And when you finally figured out what you’re doing, you can not only use those skills to program your campus LAN. You can extend them into the data center network as well thanks to consistent terminology.

It’s almost like Cisco is trying to introduce a standard set of terms that can be used to describe consistent behaviors across groups of devices for the purpose of cross training engineers. Now, where have we seen that before?

Bye Bye, CLI

Oh yeah. And, while you’re at it, don’t forget that Arista “lost” a copyright case against Cisco for the CLI and didn’t get fined. Even without the legal ramifications, the Cisco-based CLI has been living on borrowed time for quite a while.

APIs and Python make programming networks easy. Provided you know Python, that is. That’s great for DevOps folks looking to pick up another couple of libraries and get those VLANs tamed. But it doesn’t help people that are looking to expand their skillset without leaning an entirely new language. People scared by semicolons and strict syntax structure.

That’s the real reason Cisco is pushing the ACI terminology down into DNA Center and beyond. This is their strategy for finally getting rid of the CLI across their devices. Now, instead of dealing with question marks and telnet/SSH sessions, you’re going to orchestrate policies and EPGs from your central database. Everything falls into place after that.

Maybe DNA Center does some fancy Python stuff on the back end to handle older devices. Maybe there’s even some crazy command interpreters literally force-feeding syntax to an ancient router. But the end goal is to get people into the tools used to orchestrate. And that day means that Cisco will have a central location from which to build. No more archaic terminal windows. No more console cables. Just the clean purity of the user interface built by Insieme and heavily influenced by Cisco UCS Director.


Tom’s Take

Nothing goes away because it’s too old. I still have a VCR in my house. I don’t even use it any longer. It sits in a closet for the day that my wife decides she wants to watch our wedding video. And then I spend an hour hooking it up. But, one of these days I’m going to take that tape and transfer it to our Plex server. The intent is still the same – my wife gets to watch videos. But I didn’t tell her not to use the VCR. Instead, I will give her a better way to accomplish her task. And on that day, I can retire that old VCR to the same pile as the CLI. Because I think the ACI-based terminology that Cisco is focusing on is the beginning of the end of the CLI as we know it.

4 thoughts on “Is ACI Coming For The CLI?

  1. Pingback: Is ACI Coming For The CLI? - Codango™

  2. Pingback: Is ACI Coming For The CLI? - Tech Field Day

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  4. Props for excellent use of Galactus! Just wanted to chime in to say that troubleshooting ACI heavily relies on the CLI. You could use the API, but when stuff is broken you’re going to be in an SSH session with a friendly TAC engineer 🙂

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