The Fabric Interconnect (FI) is the core component of a UCS solution, providing network, storage, and unified management capabilities to servers. Fabric Interconnects are typically configured as highly available clustered pairs in production environments and provide active-active data traffic. A single FI-based design is also possible for proof of concept (POC) but not recommended for a production environment. Fabric Interconnects provide the following two capabilities:

• Network connectivity to both LAN and SAN
• UCS infrastructure management through embedded management software UCSM for both hardware and software management

With Gen 3 UCS hardware, Cisco has introduced a new series of Fabric Interconnects, Cisco UCS Fabric Interconnect 6300. This generation has been upgraded from the earlier 10 GbE-port model to a high-density 40 GbE-port model with 2.56 Tbps throughput. At the time of writing this, the customer can still select the Cisco UCS Fabric Interconnect 6200 series from the second-generation to go with the 10 Gig unified port model. The first-generation Cisco UCS Fabric Interconnect 6100 series has reached end of life and will not be supported.

The core functionality is the same in all the generations, with a difference in the number of physical ports, and can be upgraded to the latest UCSM software.

Fabric Interconnects provide converged ports. Converged means that depending on physical SFP and Fabric Interconnect software configuration, each port can be configured as an Ethernet port, an FCoE, or an FC port.

In production, Fabric Interconnects are deployed in clustered pairs to provide high availability. A Cisco-supported implementation requires that clustered Fabric Interconnects be identical. The only scenario for having different Fabric Interconnects in a cluster is during a cluster upgrade.

The Gen 3 Fabric Interconnect comes in two models: UCS FI 6332, which is 32-port 40 Gig Ethernet/FCoE, and UCS FI 6332-16UP, which comes with 16 unified ports to support 1/10 Gig Ethernet/FCoE or 4, 8, and 16 Gig native Fibre Channel. The Fabric Interconnect is a top-of-rack (ToR) switch and provides 10 Gig/40 Gig LAN connectivity northbound, where 40 Gig I/O module connectivity southbound.

The Gen 2 Fabric Interconnect comes in two models: UCS FI 6248UP, which has 32 fixed ports and 16 ports with an expansion module, and UCS FI 6296UP, which has 48 fixed ports and 48 ports with three expansion modules (16 ports per expansion module). Both models provide unified ports that can be changed to any mode through a software configuration change.