Brocade Communications Systems 53-1002163-02 manual FCoE Initialization Protocol, Flow Control

1 FCoE Initialization Protocol

NOTE

The Brocade software supports a maximum 24 LAG interfaces.

Flow Control

802.3x Ethernet pause and Ethernet Priority-based Flow Control (PFC) are used to prevent dropped frames by slowing traffic at the source end of a link. When a port on a switch or host is not ready to receive more traffic from the source, perhaps due to congestion, it sends pause frames to the source to pause the traffic flow. When the congestion has been cleared, it stops requesting the source to pause traffic flow, and traffic resumes without any frame drop.

When Ethernet pause is enabled, pause frames are sent to the traffic source. Similarly, when PFC is enabled, there is no frame drop; pause frames are sent to the source switch.

For detailed information on configuring Ethernet pause and PFC, see “Configuring QoS” on page 107.

FCoE Initialization Protocol

The FCoE Initialization Protocol (FIP) discovers and initializes FCoE capable entities connected to an Ethernet cloud through a dedicated Ethertype, 0x8914, in the Ethernet frame.

FIP discovery

NOTE

This software version supports the October 8, 2008 (REV 1.03) of the ANSI FC Backbone Specification with priority-tagged FIP VLAN discovery protocol and FIP version 0. This release supports FIP Keep Alive.

The Brocade FCoE hardware FIP discovery phase operates as follows:

•The Brocade FCoE hardware uses the FCoE Initialization Protocol (FIP). Enodes discover FCFs and initialize the FCoE connection through the FIP.

•VF_port configuration—An FCoE port accepts Enode requests when it is configured as a VF_port and enabled. An FCoE port does not accept ENode requests when disabled.

•Solicited advertisements—A typical scenario is where a Brocade FCoE hardware receives a FIP solicitation from an ENode. Replies to the original FIP solicitation are sent to the MAC address embedded in the original FIP solicitation. After being accepted, the ENode is added to the VN_port table.

•Login group—When enabled, replies to solicitations are sent only by Brocade FCoE hardware that have the ENode in the login group.

•FCF forwarding—The Brocade FCoE hardware forwards FIP frames only when the VLAN is set to FCF forwarding mode.

•VLAN 1—The Brocade FCoE hardware should not forward FIP frames on VLAN 1 because it is reserved for management traffic only.

•A fabric-provided MAC address is supported. A server-provided MAC-address is not supported in the Fabric OS v7.0.0 release.

8	Converged Enhanced Ethernet Administrator’s Guide
	53-1002163-02