Addendum

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 MXL and
I/O Aggregator switches, 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 flexbile solution in interoperating with third-party switches that
enable the splitting of LAN and SAN traffic. With the MXL 10/40GbE Switch and I/O Aggregator being
well-established appliances 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
MXL 10/40GbE Switch and I/O Aggregator provide thirty-two 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 MXL 10/40GbE Switch and I/O Aggregator.
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 MXL 10/40GbE Switch and I/O Aggregator.
Each module supports four FC ports.
• Each port can operate in 2G, 4G, or 8G of Fibre Channel speed.
• All ports on an FC Flex IO module can function in 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 is a maximum of 64 server fabric login (FLOGI) requests or fabric discovery (FDISC) requests per
server MAC address before being 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.
478
Understanding and Working of the FC Flex IO Modules