[c-nsp] Stacking 3750X vs diverse 4948E

[Tony Varriale]

On 5/18/2012 1:55 PM, David Coulson wrote:
> In a datacenter environment, we typically deploy 4948 top-of-rack 
> switches with L2 uplinks to our 6500 core - Systems get connections 
> into two different switches and rely on OS NIC bonding (mostly Linux) 
> to support switch failures. Switches running STP and in the last four 
> years we've had no issues with this design (including failures of 
> systems connected to diverse switches).
>
> A new proposed configuration utilizes stacked 3750X switches, where 
> servers would be connected to multiple switches within the same stack. 
> I have next to no experience in the low-end switches that do stacking, 
> but from a general risk management perspective, it seems like a many 
> eggs and single basket configuration.
>
> Does anyone have any solid experience with 3750X switches, or stacking 
> in a datacenter in general? I've seen plenty of stacks for 
> closets/end-users, but I don't see many in a top-of-rack config. Is 
> Cisco stacking typically 'reliable', in that when a switch fails it 
> will leave the remainder of the stack functional? What about a 
> software issue? Does the whole stack crap out and reload, or does the 
> master just fail and a new one get elected?
>
> I realize it's a pretty broad question, but it boils down to - Is a 
> stacked switch config significantly less reliable/resilient/available 
> than two TOR switches?
>
> David
>

The first and most important question is: Is this a real datacenter?  If 
so, 3750xyz is not for you.

Also, the regular 4948s are not much better.

tv