Dell Configuration Guide for the S4048–ON System 9.14.2.5

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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. You can configure ACLs to emulate point-to-point links, providing control over the traffic received or transmitted into the switch. To automatically 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 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.

Table 1. FIP FunctionsFIP Functions
FIP Function	Description
FIP VLAN discovery	FCoE devices (ENodes) discover the FCoE VLANs on which to transmit and receive FIP and FCoE traffic.
FIP discovery	FCoE end-devices and FCFs are automatically discovered.
Initialization	FCoE devices learn ENodes from the FLOGI and FDISC to allow immediate login and create a virtual link with an FCoE switch.
Maintenance	A valid virtual link between an FCoE device and an FCoE switch is maintained and the LOGO functions properly.
Logout	On receiving a FLOGI packet, FSB deletes all existing sessions from the ENode to the FCF.

Illustration of a FIP discovery and login between an ENode and an FCF. — Figure 1. FIP Discovery and Login Between an ENode and an FCF