Stacking C7000 Enclosures, which interfaces to use

[LandonWO]

We recently just purchased two C7000 enclosures, each with two Flex-10 VirtualConnect cards. We're currently in the process of installing and configuring the chassis, but I have some questions on how to configure the VirtualConnect cards. Each card came with only three Ethernet SFP modules, but I think that's because our vendor got a bit confused on what we needed. We'd like to stack the two chassis together, but I'm not sure exactly how I should do that. Ideally, I'd like to use the CX4 interface for stacking, and then use the other 8 SFP slots with an Ethernet module for uplink. Is this an ok solution, or should I be using x7 and x8 slots for stacking and forget about using the CX4 interface? If anyone could give me some input on this, it would be greatly appreciated. Thanks.

[Anandr78]

X7 and X8 should not be used for stacking if you need redundancy in virtual connect. Interlink between the two Virtual Connect within the enclosure will be broken if you use these ports. You need to use only CX4 port for stacking the two enclosures.

[LandonWO]

Could you explain what you mean by redundancy in virtual connect? Should I be hooking the two Flex10 cards together? If so, I assume I'm going to need SFPs for x7 and x8, correct? I can see us using the CX4 port for hooking two chassis together, but what do we do when we add a third chassis?

[Anandr78]

Flext10 VC modules in an anclosure if placed adjacent, connects to each other internally and acts in active-standby mode. X7 and X8 can either be used for either 1) interlink which doesnt need a physical cable connection but internally connected (or) 2) an uplink PORT. If any uplink is connected to these ports, the interlink is automatically disconnected. This would mean that there are two VCs which are both active and has two different domains altogether which doesnt share any resources for ex: vNets.

[LandonWO]

Ah ok, that makes sense. So I should not be putting any SFPs in x7 and x8 then and be using the CX4 cable for stacking then? That makes sense for right now, but each Flex10 module only has 1 CX4 interface. How would I add a third chassis into the stack?

[Anandr78 · Accepted solution]

"Virtual Connect Multi-Enclosure Stacking Reference Guide" clearly explains on how you do multiple enclosure stacking...This document should be available in HP site. CX4 and Port1 are shared. Incase of 3 enclosure stacking, you would need two ports which can be port1 and port2. I have attached a document but please look for the latest one if available. 

[LandonWO]

Ah ok, that makes sense. Thank you very much for your help.