[c-nsp] Learning L2 switching and spanning tree by doing

[Jeff Kell]

Dean Smith wrote:
> If you've ever had a real network....and accidentally created a loop in an
> environment without spanningtree....and then watched the network melt and
> all the activity lights go solid....spanning-tree becomes much easier to
> understand.

You can learn a lot about spanning tree by RTFM, but that only goes so far.

If you can find a "FM" that discusses converting from, say, default PVST 
to cross-vendor MST, on a live network across a large campus without an 
engineer in every closet with a laptop, serial console, and cell phone, 
let me know :-)

The result is typically an unplanned meltdown where everything tries to 
talk to everything, or closets of bricks that refuse to talk to anyone...

Jeff