Last week we talked about orienteering — using models and information to orient ourselves to what’s going on in the network. This is part of the OODA loop, which we talked about two weeks ago. This week, let’s look at the next step — decide.
In fact: Decide! Now! How many hours have you spent thinking through what to decide? Which car to buy, which house to buy, which vacation to take, which… It seems like our life is a continuous stream of decisions through which we must dig deeply to make a choice. Sometimes it makes you want to replace your entire outfit with grey and black. Everything. Actually, we should feel blessed to have so many decisions — at least we’re not considering “eveningvear…” (note the ever fashionable flashlight).
But the last place you want to be is in the middle of a major network outage or attack, spending hours deciding — what was it we were deciding? By the time you get to the fifth pizza and the tenth box of bonbons, maybe you’ve forgotten what you are sitting in that “war room” for. There is another alternative, of course.
Decide what you’re going to decide before you have to decide.
Okay, that might sound a little “round about,” but let’s take an example from self defense training to illustrate. There are four levels of in the cycle of self defense. White — you’re unaware of your environment. You should never be here. Yellow — you’re aware of your environment, actively thinking about potential threats. Red — you’ve spotted what you think is a threat, and are preparing to react. Finally, black — you believe you are actually under attack, and are actively reacting to that attack. What’s important here, from the perspective of the OODA loop, is that between red and black you need to make a plan. You need, for instance, to look for cover and/or concealment. You need to think about how you’re going to exit the situation, whether it’s pulling off on the shoulder and driving away, or finding the exit, or…
To give another example — when you’re sitting there listening to the safety briefing before takeoff for the nine millionth time, what are you doing? Are you looking at where the exits are, and thinking about how you can get there when that person two aisles in front of you just shoved the largest suitcase you’ve ever seen under the growing seat in front of them? Or are you playing Candy Crush?
In all these situations, you should be deciding before you have to decide so you can shorten the OODA loop.
- Where would you put a filter to block this particular type of traffic?
- Which parallel links would you remove to kill off that positive feedback loop that’s keeping your routing protocol from converging?
- What servers can you shut down for a time while you’re trying to figure out why the data center fabric has become so hot all of a sudden?
All of these decisions are choices you can make before the action starts — before you actually have to decide to do something. In other words decide what you need to do, so that when it comes time to actually do it, you’ll have a plan in place.
The OODA loop is covered in some detail in The Art of Network Architecture, available wherever fine books are sold (because if they don’t sell my books, then they don’t sell fine books — see how that works?).