This week I have been reviewing my IP Multicast and generally grumbling about how pointless Multicast is. Off course this is partly SSA and part hostility at my inability to learn efficiently as I get older.

I recently read this blog post “Just in case” versus “just in time” by John D Cook at The Endeavour. Here is the nut that really came home for me:

“The difference between just-in-case and just-in-time is like the difference between training and trying. You can’t run a marathon by trying hard. The first person who tried that died. You have to train for it. You can’t just say that you’ll run 26 miles when you need to and do nothing until then.”

What am I studying this for ?

There are a lot people who are studying various areas of Networking, typically CCNA, CCNP, CCIP and CCIE. I’m sure that every person has once said “What am I studying this for ? I’m never going to need to know this”. And there is a very good chance that you are going to be right. I’ve NEVER installed an IP Multicast network, but I HAVE done several designs where Multicast was discussed and discarded. I needed that Multicast knowledge right then and there and I couldn’t halt proceedings and get that knowledge later. I could always go for details later, but I need good knowledge right then and there.

Learning and Studying Needs Practice

There have been times in my career when I have stopped / slowed my learning. I got tired of the reading, researching and thinking. In those periods I just coasted along and learned what I had to learn when the job needed it. This seems like a good thing but it didn’t work out for two reasons.

The first reason is that I found that my career was slowing down and I wasn’t keeping up with new technologies being developed. It was pretty obvious that other people were getting better jobs, more money and more recognition because I wasn’t knowledgeable in the new stuff.

The second reason was more invidious. I lost the ability to study. I got worse at concentration and focus. It took me some time to realise that I was losing the habit of “studying”.

Design means knowing [almost] everything

In a design team, you don’t truly need to know everything, all the time. It is possible to use “Just In Time” methods to go and learn what you need to know. Some googling, some training course, a text book might be able to get the knowledge that you need.

But you MUST know certain fundamentals to perform the “Just in Time” learning. That is, you can’t learn IP Multicast without knowing IP, UDP, addressing, broadcast, and the various other concepts that go with this.

Knowledge more important than experience

In October 2008, I wrote four articles on how Knowledge is more important than Experience. Experience is an example of “Just in Time” learning. That’s a fine way to learn because it’s easy, and you are completely involved in the process. However, without a core knowledge base to draw on, this type of learning isn’t always perfect.

For an example of experience vs knowledge: if you had learned Spanning Tree ten years ago, you might be tempted to think that Rapid Spanning Tree is the same thing. In fact, RSTP 802.1w is very different from 802.1d. There are only three interface states’ LAN ports are Designated, Alternate or Discarding for better convergence; and has support for Multiple Instances with either MST or RPVST/RPVST+ for just a couple of key differences.

Learning the new material from a textbook or a training course means that you are “ready to go” and that someone like me doesn’t have to teach you. Or wait for you to read it, or find the money to send you on a training course. And that means you have less change of getting that promotion or that pay rise.

Lifelong Learning

These days I follow a strategy of lifelong learning. I try to learn a lot of different technologies so that I have some grounding in a wide range of technologies. This approach has taken me to a lot of new pathways in my life. I’ve got to admit, that if you had told me ten years ago that I would STILL be hitting the textbooks nearly every day, I wouldn’t have believed you. Now, I’m not always happy about it, but it’s worth it.

And that’s part of the reason that KNOWLEDGE is more important that EXPERIENCE. You can GET experience if you KNOW what you are doing. Getting KNOWLEDGE by EXPERIENCE doesn’t really work.