White Papers

By installing an FC Flex IO module, you can enable the FN IOM to directly connect to an existing FC SAN network. The FC Flex
IO module uses the existing slots on the FN IOM and provides four or eight FC ports up to speed of 8 GbE per second. You can
connect all of the FC ports to the same FC SAN fabric to yield FC bandwidth of up to 64GB. It is possible to connect some of
the ports to a different FC SAN fabric to provide access to multiple fabric devices.
In a typical Fibre Channel storage network topology, separate network interface cards (NICs) and host bus adapters (HBAs)
on each server (two each for redundancy purposes) are connected to LAN and SAN networks respectively. These deployments
typically include a ToR SAN switch in addition to a ToR LAN switch. By employing converged network adapters (CNAs) that the
FC Flex IO module supports, CNAs are used to transmit FCoE traffic from the server instead of separate NIC and HBA devices.
In such a scenario, you can determine whether the FC or SAN packets and the Ethernet or LAN packets must be split within the
chassis or by using a ToR switch to perform this splitting.
If you want to segregate the LAN and SAN traffic within the chassis, you can employ switches such as the Dell M8428-k
Converged 10GbE Switch or FC-only switches such as the Dell M5424 switch module. You can also use the S5000 Switch as a
ToR switch to separate the LAN and SAN traffic at the ToR. By using the FC Flex IO module, you can optimally and effectively
split the LAN and SAN traffic at the edge of the blade chassis itself. You can deploy the FC Flex IO module can be deployed in
the enterprise and data center switching networks to leverage and derive the advantages of a converged Ethernet network.
The FC Flex IO module is not an FCF switch, but it offers FCoE capabilities from the server to the FN IOM, and native
FC capability in the uplink direction to the SAN switches. Although the FC Flex IO module does not support all of the FCF
characteristics, such as full-blown name services or zone parameters, it presents the most flexible solution in interoperating with
third-party switches that enable the splitting of LAN and SAN traffic. With the FN IOM being well-established systems in the
switch domain, you can install the FC Flex IO module to enhance and increase the converged Ethernet network performance and
behavior. With the FC Flex IO module, the FN IOM provide 8 1GbE or 10 GbE server-facing ports and the option to add two FC
Flex IO modules that offer up to 8 8Gb Fibre Channel ports for uplink traffic in addition to the fixed two 40GbE ports on the FN
IOM.
You can configure one of the following upstream (fabric-facing) FC ports:
● Two 40GbE and eight 8GB FC ports
● Four 40GbE and four 8GB FC ports
● Two 40GbE, four 10GbE, and four 8GB FC ports
● Two 40GbE, four 10GBASE-T, and four 8GB FC ports
FC Flex IO Module Capabilities and Operations
The FC Flex IO module has the following characteristics:
● You can install one or two FC Flex IO modules on the FN IOM. Each module supports four FC ports.
● Each port can operate in 2Gbps, 4Gbps, or 8Gbps of Fibre Channel speed.
● All ports on an FC Flex IO module can function in the NPIV mode that enables connectivity to FC switches or directors, and
also to multiple SAN topologies.
● It automatically senses the current speed when the port link is up. Valid link speeds are 2 Gbps, 4 Gbps, and 8 Gbps.
● By default, the FC ports are configured to operate in N-port mode to connect to an F port on an FC switch in a fabric. You
can apply only one FCoE map on an FC port. An N-Port is a port on the node of an FC device and is called a node port.
● There should a maximum of 64 server fabric login (FLOGI) requests or fabric discovery (FDISC) requests per server MAC
address before forwarded by the FC Flex IO module to the FC core switch. Without user configuration, only 32 server
login sessions are permitted for each server MAC address. To increase the total number of sessions to 64, use the max
sessions command.
● A distance of up to 300 meters is supported at 8 Gbps for Fibre Channel traffic.
● Multiple domains are supported in an NPIV proxy gateway (NPG).
● If the switch contains FC Flex IO module, you cannot create a stack and a log message states that %Error: cannot
configure stack group when FC module is enabled. Similarly, FC Flex IO modules do not function when you
insert them into a stack of I/O Aggregator switches.
920
FC Flex IO Modules