[c-nsp] Maximum spannig tree instances

[Ross Vandegrift]

On Tue, Jul 14, 2009 at 05:00:36PM +0200, Gert Doering wrote:
> <rant>
> MST is what comes out if vendor committees get together, and agree to
> implement the least common determinator in the most complicated way.
> </rant>

I completely disagree - it's what comes out of solving problems
related to the LAN - the LOCAL area network.  In virtualized LANs,
there's typically only a few possible physical topologies that can
exist.  MST seeks to exploit this to lower the amount of processing
power that is required.

My employer is a datacenter service provider and this holds in our
scenario - there's only ever two possible physical topologies.  Two
distribution routers each have a connection to hundreds of access
switches.  We started out by mapping what VLANs went to which physical
topology and we're done forever.  It's great -  we get redundancy
everywhere and mostly even load balancing.

If your network doesn't behave like this, then you need a better
control plane than MST can provide.  But don't complain about standards
bodies just because they solved a problem that doesn't concern you.

-- 
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