Blade ICE G8124-E Manuale Utente

BMD00220, October 2010

Chapter 14: FCoE and CEE  

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Data Center Bridging Capability Exchange (DCBX) protocol is a vital element of CEE. DCBX 
allows peer CEE devices to exchange information about their advanced capabilities. Using DCBX, 
neighboring network devices discover their peers, negotiate peer configurations, and detect 
misconfigurations.

DCBX provides two main functions on the G8124:

Peer information exchange

The switch uses DCBX to exchange information with connected CEE devices. For normal 
operation of any FCoE implementation on the G8124, DCBX must remain enabled on all ports 
participating in FCoE.

Peer configuration negotiation

DCBX also allows CEE devices to negotiate with each other for the purpose of automatically 
configuring advanced CEE features such as PFC, ETS, and (for some CNAs) FIP. The 
administrator can determine which CEE feature settings on the switch are communicated to and 
matched by CEE neighbors, and also which CEE feature settings on the switch may be 
configured by neighbor requirements.

The DCBX feature requires CEE to be turned on (see 

).

When CEE is turned on, DCBX is enabled for peer information exchange on all ports. For 
configuration negotiation, the following default settings are configured:

Application Protocol: FCoE and FIP snooping is set for traffic with 802.1p priority 3

PFC: Enabled on 802.1p priority 3

ETS



Priority group 2 includes priority values 0 through 2, with bandwidth allocation of 10%



Priority group 3 includes priority value 3, with bandwidth allocation of 40%



Priority group 4 includes priority values 4 through 7, with bandwidth allocation of 50%