[c-nsp] Maximum spannig tree instances

[Ross Vandegrift]

On Fri, Jul 17, 2009 at 09:09:30AM -0500, Geoffrey Pendery wrote:
> "The point of MST is to realize that there's never going to be more
> than two possible forwarding topologies, and computing more is a total
> waste."
> 
> But that statement is specific to your network design and your
> topology.  Surely you're not claiming that it's never possible to
> build a network with more than two topologies?

No, absolutely not.  I was answering the assertion that there is
something fundamentally wrong with MST in terms of the protocol or the
design goal.  It's design goal is sensible, and it's execution
acheives that goal.

If that goal is a hammer and you have screws, by all means, use a
screwdriver!

> When you're given the mandate/requirement/strong-preference of using
> open standard protocols rather than Cisco proprietary ones (not an
> unreasonable goal) it leads to great frustration, because you end up
> having to hammer in screws.  This frustration apparently leads to some
> ranting on email lists.

Indeed - especially with MST, as various vendors have historically
done a poor job in implementation.  You're left with a working Cisco
protocol on one hand, and an IEEE protocol that's sometimes only 90%
there.

-- 
Ross Vandegrift
ross at kallisti.us

"If the fight gets hot, the songs get hotter.  If the going gets tough,
the songs get tougher."
	--Woody Guthrie