3750x Design help needed - VSS style - traffic both links

[jacob6000]

Hello,

I need a little help figuring out the best way to do this. I have two core 3750X switches (SWA and SWB). These two switches each have four switches hanging off of them. I need to add two more switches for a separate server/app farm. These two new 3750x (?)(SWC & SWD) switches will each have a Layer-2 connection to the core switches (SWA-DC1 & SWB-DC2) and also service their own subnet/vlan for the server farm. It may be SWC to SWA and SWD to SWB  or it could be that SWC & SWD both have a link to each core switch. All this is in the same Data Center. I just called it DC1 and DC2 to define logical separation for each side.

Is there a way to configure this scenario so that at least one uplink from SWC and SWD are both passing traffic and not have STP block one link since it is all Layer-2 between the core and distribution switches? this would allow the switches hanging off SWA & SWB to each use their link to the core and not have everything traverse a single and distribute my bandwidth more evenly.

Any feedback/ideas are appreciated.

Thank you,

[Reza Sharifi]

Hi,

since you are using the 3750 series, you have the option of stacking the core switches (SWA and SWB).  In this case you can simply uplink every switch to both cores using Etherchannels. And so, both links are used and there is no blacking by STP since both links are logically one.

HTH