Administrator Guide

Processing of Data Trac
The Dell Networking OS determines the module type that is plugged into the slot. Based on the module type, the software performs
the appropriate tasks. The FC Flex IO module encapsulates and decapsulates the FCoE frames. The module directly switches any
non-FCoE or non-FIP trac, and only FCoE frames are processed and transmitted out of the Ethernet network.
When the external device sends FCoE data frames to the switch that contains the FC Flex IO module, the destination MAC address
represents one of the Ethernet MAC addresses assigned to FC ports. Based on the destination address, the FCoE header is
removed from the incoming packet and the FC frame is transmitted out of the FC port. The ow control mechanism is performed
using per-priority ow control to ensure that frame loss does not occur owing to congestion of frames.
Operation of the FIP Application
The NPIV proxy gateway terminates the FIP sessions and responses to FIP messages. The FIP packets are intercepted by the FC
Flex IO module and sent to the Dell Networking OS for further analysis. The FIP application responds to the FIP VLAN discovery
request from the host based on the congured FCoE VLANs. For every ENode and VN_Port that is logged in, the FIP application
responds to keepalive messages for the virtual channel. If the FC link becomes inactive or a logging o of the switch occurs, the FIP
engine sends clear virtual link (CVL) messages to the host. The FIP application also responds to solicited advertisements from the
end-device. In addition, the FIP application periodically sends advertisement packets to the end-devices for each FCF that is part of
the NPIV proxy gateway.
If FC Flex IO modules are installed, the I/O Aggregator does not perform FIP snooping because the FIP frames are terminated on the
switch for NPIV operations. However, on MXL Switches, you can congure the switch to operate in FIP Snooping or NPIV mode.
If the MXL 10/40GbE Switch functions in the NPIV mode and you attempt to set the uplink port to be an FCF or a bridge port, a
warning message displays and the settings are not saved. On the Aggregator, if the FC module is present, the uplink ports are not
automatically set up as FCF or bridge ports. The FC Flex module cannot function as both an NPIV proxy gateway and a FIP snooping
bridge at the same time.
Operation of the NPIV Proxy Gateway
The NPIV application on the FC Flex IO module manages the FC functionalities congured in Dell Networking OS. After the FC link
comes up, the gateway sends the initial FLOGI request to the connected switch using the switch and port WWN methods. After a
successful login, the NPIV gateway sends a notication to inform the CNA that the FCF available to log in. The source address of the
FIP advertisement and FIP discovery advertisement response contain the MAC address of the FC Flex IO module port. Depending
on the number of login sessions on a particular FCF, the NPIV gateway can load-balance the login sessions from ENodes.
The NPIV application performs the FLOGI to FDISC conversion and sends the new FC frame on the associated FC ports. After the
external switch responds to the FLOGI request, the NPIV gateway establishes the NPIV session and sends the frame to the FIP
application. The FIP application establishes virtual links to convert FCoE FLOGI accept messages into FIP FLOGI accept messages.
The corresponding ACL for the accept message is then applied. If a FIP timeout from ENode or VN_PORT occurs, the NPIV
application performs the FC fabric logout to the external FC switch. The NPIV application manages the sessions between the FCoE
and the FC domain.
Installing and Conguring the Switch
After you unpack the MXL 10/40GbE Switch, refer to the ow chart in the following gure for an overview of the steps you must
follow to install the blade and perform the initial conguration.
FC Flex IO Modules
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