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New Member

UCS: switching/routing question


I am trying to get a definitive answer to how switching and routing occurs in the UCS environment described below. I am also looking for a"primer" on the functions and overall process the IC plays in the UC.

We currently have 2x6120 conected to 6 chassis'. Most of them are ESX hosts with multiple VM's, each with VM's in different vlans. We are using the 1000v instead of the regular VDS. The IC's connect to a 7K with vlan SVI's. So, if there is a vm in vlan A that needs to communicate with a VM in vlan B, what is the route the data would take? Would they goto the 7K since that's where the SVI is or is  the IC smart enough to make the switching decision?

Thanks in advance.


UCS: switching/routing question


Let me make it very simple for you.

UCS FI does no routing and for the switching its can switch packets for the same vlan on the same side of the fabric. i.e if the traffic between VM-A and VM-B is for vlan x and they noth are sending the traffic out to FI-A it will be switched locally otherwise it will have to go upstream for switching.

A quick answer to your question: For the traffic between vlana and vlanb, it will have to go upstream to 7k for routing.


New Member

UCS: switching/routing question

Hello Sudip,

Regarding introductions to the way the Fabric Interconnects work, check out the I/O Management section at the following page:

M. Sean McGee does a pretty good series on fundamental aspects of the UCS System.

By the way, the fabric interconnects are usually abbreviated as FI, not IC.  This can help eliminate a little confusion when you talk to other UCS users.  :-)




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New Member

UCS: switching/routing question

Thank you guys for the clarifiction.

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