Tom Ammon despatched me his ideas on choosing the proper degree of abstraction in your community automation answer as a response to my What Is Intent-Based mostly Networking weblog put up, and allowed me to publish them on ipspace.web.
I completely agree along with your what vs how instance with OSPF. I work on a NOS group the place if we needed, lets say, as an alternative of “run OSPF on these hyperlinks”, do that:
- Ship hiya messages on these hyperlinks
- Detect neighbors
- Transition by the neighbor states
- Type adjacencies
- Calculate finest paths.
However, we’d by no means do this. To do this at even medium scale would make the deployed community more and more fragile as you add nodes, and it’s simply plain a number of work – toil that returns no discernible operational profit.
To me that is very very similar to the excellence between declarative and crucial approaches. You continue to must have crucial logic sooner or later as you close to the underside of the stack (you possibly can’t simply say to a CPU register “hey, give me the most effective path between A and Z!”) however you get a number of good advantages by constructing issues in such a approach you can belief and considerably ignore the decrease layers of the tech stack as you place your human concentrate on the stuff larger up.
Recently, I’ve been excited about automation (at the least, the configuration administration a part of automation) extra when it comes to layers of abstraction, and one’s working place in these layers. I believe the conclusion I’m coming to is that this: You must function your community on the highest layer of abstraction potential that can mean you can hit your reliability, availability, and different enterprise targets.
It takes $(effort) to automate (and preserve!) an answer to autoprovision department routers/switches/SD-WAN home equipment, configure appropriate BGP friends, configure endpoint ports, and so forth.. It takes $(effort)+N to construct orchestration that can allow you to say “construct me a department workplace utilizing the conventional sample”. But it surely ought to be a aware alternative and I believe proactively selecting the layer of abstraction you wish to work at might be actually empowering. It’s actually only a matter of how excessive an abstraction you wish to trip (and crash) on.
