Difference between Fabric Extender and Fabric Interconnect

[ikramhussain]

Can Someone make me clear the Difference between Fabric Interconnect and Fabric Extender???

[Walter Dey]

In the context of UCS:

FI is the central control of a UCS domain

- it is a L2 Ethernet switch

- most configuration have a cluster of 2 interconnected FI's

- FI also supports classical fibre channel and FCoE

- FI has North bound links to interconnect Datacenter

- FI has South bound links to connect chassis (up to max 20 chassis per UCS domain) IOM

- UCS manager runs as a application on FI

FEX which is called IOM in UCS

- each chassis has 2 IOM's

- links chassis to FI

- is not a switch, but a extenter to a FI interface

[barry-peters]

It would be nice to see a diagram of a UCS chassis connecting to the IOM's on the side, then connceting to the FI's, then the FI's connecting to an EOR switch (access / leaf). I'm familiar with the UCS IOM's connecting to FEX's, which then connect to an EOR (leaf) switch. However, the FI concept is a bit puzzling; is it a leaf switch or is it an extension of an EOR (leaf) switch like the FEX's?

Clarification, please.

[Kirk J]

Greetings.

You can think of the Fabric Interconnects as nexus 5K switches, and the IOMs as Fexes, that get their programming from the Fabric Interconnects.

The Fabric Interconnects are running Nexus code underneath, but have the UCSM GUI and CLI, that help automate a lot of configurations that would normally take a lot of configuration steps if you were connecting servers to standard nexus 5Ks.

See http://www.cisco.com/c/dam/en/us/products/collateral/servers-unified-computing/ucs-b-series-blade-servers/spec_sheet_c17-644224.pdf 3rd page for some pictures of what the chassis and IOM modules look like.

I don't know that the FIs exactly fit the TOR or EOR model, but would be closer to Top of Rack.

The FI designated uplink ports will be the north bound connected ports that would typically go to regular N5k or N7k, etc.

http://www.cisco.com/c/en/us/solutions/data-center-virtualization/unified-computing/dc_tech_ov.html

Thanks,

Kirk