Re: Cisco Nexus

[George Herbert <george.herbert () gmail com>]

> Brandon Ewing <nicotine () warningg com> wrote:
>
> > David Bass wrote:
> > The n2k ToR is not a great design for user or storage interfaces if most of your traffic is east/west.  It is great 
> > as a low cost ilo/drac/choose your oob port, or if most of your traffic is north/south.  Biggest thing to remember 
> > is that it is not a switch, and has limitations such as not connecting other switches to it. Like anything else you 
> > have to understand the product so that you don't engineer something that it wasn't designed to do.
>
> And remember -- The Nexus 2K performs absolutely ZERO local switching -- all
> frames received from client ports are just copied to the upstream device, so
> it can handle the frame/packet forwarding logic.                                 


What this really does is force you to consider how much of your East-West is rack-local, versus off rack.

Rack-local-heavy hurts as badly as off rack, with FEX.

If you want to / can localize E/W tighter than that then you want real TOR switching.  If the average E-W is cross rack 
then the FEX are performance equivalent.  For random distributions this comes at a few racks.  For intentional 
distributions it's probably better to TOR switch from day one.


George William Herbert
Sent from my iPhone