unstacked or stacked access switches

[Shane Graham]

Reference the attached diagram.

Currently, we have a pair of Nexus 5K switches with virtual port-channels to a pair of unstacked Avaya 4850GTS-PWR switches.  This requires four Cisco SFP+'s, and four Cisco SFP's for 10Gb connectivity.  Half of the client pc's, (odd numbers), are connected to the top Avaya access switch, and the other half, (even numbers), are connected to the bottom Avaya access switch.  Each client pc has a spare cable connected to the other switch, in case of an access switch failure, only half of the users will loose connectivity, until they move to the spare cable.

We are replacing these Avaya switches, with a pair of Cisco 2960XR-48FPD-I switches.  In this configuration, would it be more efficient to leave them unstacked, or to stack them?  With Cisco switch stacks, we can reload member switches individually, so the users can move to their spare cable, and no one loses connectivity, unless we're making a global change like the MTU size, which would require the whole stack to be reloaded.

We're looking for input/feedback on this approach.

[Reza Sharifi]

In this scenario where you have 2 connections per PC and as long as you don't have more than 48PCs, the simplest config is to stack the 2960 switches and connect one cable to one switch and the other cable to the other switch. This way you just mange one switch and if one switch fails the other switch can take over. Now, this type high availability applies mostly to servers with 2 NICs, which you can use to create a Portchannel per device but not sure if you can do the same with PCs.

HTH

[Shane Graham]

The client pc's, (really thinclients,) don't have dual nic's, only a spare disconnected Ethernet cable.

[Reza Sharifi]

Ok, than in that case you can put half PCs on one switch and the half on the other switch and when one switch in the stack fails physically move the cables from one switch to the other.

[Shane Graham]

That's exactly what we're doing now.  I was asking for advice, if we should stack the replacement Cisco switches, or leave them unstacked.

[Reza Sharifi]

I would say stack them.  This way you just manage one device with one IP.