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FCoE Transit
The Fibre Channel over Ethernet (FCoE) Transit feature is supported on the S5000 switch on Ethernet interfaces. When you
enable the switch for FCoE transit, the switch functions as a FIP snooping bridge.
NOTE: FIP snooping is not supported on Fibre Channel interfaces, in an S5000 switch stack, or on links between VLT peer
switches.
Topics:
• Fibre Channel over Ethernet
• Ensure Robustness in a Converged Ethernet Network
• FIP Snooping on Ethernet Bridges
• FIP Snooping in a Switch Stack
• Using FIP Snooping
• FCoE Transit Configuration Example
Fibre Channel over Ethernet
FCoE provides a converged Ethernet network that allows the combination of storage-area network (SAN) and LAN traffic on a
Layer 2 link by encapsulating Fibre Channel data into Ethernet frames.
FCoE works with the Ethernet enhancements provided in data center bridging (DCB) to support lossless (no-drop) SAN and
LAN traffic. In addition, DCB provides flexible bandwidth sharing for different traffic types, such as LAN and SAN, according to
802.1p priority classes of service. For more information, refer to the Data Center Bridging (DCB) chapter.
Ensure Robustness in a Converged Ethernet Network
Fibre Channel networks used for SAN traffic employ switches that operate as trusted devices. To communicate with other end
devices attached to the Fibre Channel network, end devices log into the switch to which they are attached.
Because Fibre Channel links are point-to-point, a Fibre Channel switch controls all storage traffic that an end device sends and
receives over the network. As a result, the switch can enforce zoning configurations, ensure that end devices use their assigned
addresses, and secure the network from unauthorized access and denial-of-service (DoS) attacks.
To ensure similar Fibre Channel robustness and security with FCoE in an Ethernet cloud network, FIP establishes virtual
point-to-point links between FCoE end-devices (server ENodes and target storage devices) and FCoE forwarders (FCFs) over
transit FCoE-enabled bridges.
Ethernet bridges commonly provide ACLs that can emulate a point-to-point link by providing the traffic enforcement required to
create a Fibre Channel-level of robustness. In addition, FIP serves as a Layer 2 protocol to:
● Operate between FCoE end-devices and FCFs over intermediate Ethernet bridges to prevent unauthorized access to the
network and achieve the required security.
● Allow transit Ethernet bridges to efficiently monitor FIP frames passing between FCoE end-devices and an FCF. To
dynamically configure ACLs on the bridge to only permit traffic authorized by the FCF, use the FIP snooping data.
FIP enables FCoE devices to discover one another, initialize and maintain virtual links over an Ethernet network, and access
storage devices in a storage area network (SAN). FIP satisfies the Fibre Channel requirement for point-to-point connections by
creating a unique virtual link for each connection between an FCoE end-device and an FCF via a transit switch.
FIP provides functionality for discovering and logging into an FCF. After discovering and logging in, FIP allows FCoE traffic to
be sent and received between FCoE end-devices (ENodes) and the FCF. FIP uses its own EtherType and frame format. The
following illustration shows the communication that occurs between an ENode server and an FCoE switch (FCF).
The following table lists the FIP functions.
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