14FCoE TransitThe Fibre Channel over Ethernet (FCoE) Transit feature is supported on Ethernet interfaces. When youenable the switch for FCoE transit, the switch functions as a FIP snooping bridge.NOTE: FIP snooping is not supported on Fibre Channel interfaces or in a switch stack.Fibre Channel over EthernetFCoE 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 traffictypes, such as LAN and SAN, according to 802.1p priority classes of service. DCBx should be enabled onthe system before the FIP snooping feature is enabled. For more information, refer to the Data CenterBridging (DCB) chapter.Ensure Robustness in a Converged Ethernet NetworkFibre Channel networks used for SAN traffic employ switches that operate as trusted devices. Tocommunicate with other end devices attached to the Fibre Channel network, end devices log into theswitch to which they are attached.Because Fibre Channel links are point-to-point, a Fibre Channel switch controls all storage traffic that anend device sends and receives over the network. As a result, the switch can enforce zoningconfigurations, ensure that end devices use their assigned addresses, and secure the network fromunauthorized access and denial-of-service (DoS) attacks.To ensure similar Fibre Channel robustness and security with FCoE in an Ethernet cloud network, FIPestablishes virtual point-to-point links between FCoE end-devices (server ENodes and target storagedevices) 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 trafficenforcement required to create a Fibre Channel-level of robustness. You can configure ACLs to emulatepoint-to-point links, providing control over the traffic received or transmitted into the switch. Toautomatically generate ACLs, use FIP snooping. In addition, FIP serves as a Layer 2 protocol to:• Operate between FCoE end-devices and FCFs over intermediate Ethernet bridges to preventunauthorized access to the network and achieve the required security.• Allow transit Ethernet bridges to efficiently monitor FIP frames passing between FCoE end-devicesand 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 Ethernetnetwork, and access storage devices in a storage area network (SAN). FIP satisfies the Fibre ChannelFCoE Transit 313
