Users Guide

Data Center Bridging Exchange Protocol (DCBx)
The data center bridging exchange (DCBx) protocol is disabled by default on the S4810; ETS is also disabled.
DCBx allows a switch to automatically discover DCB-enabled peers and exchange conguration information. PFC and ETS use DCBx
to exchange and negotiate parameters with peer devices. DCBx capabilities include:
• Discovery of DCB capabilities on peer-device connections.
• Determination of possible mismatch in DCB conguration on a peer link.
• Conguration of a peer device over a DCB link.
DCBx requires the link layer discovery protocol (LLDP) to provide the path to exchange DCB parameters with peer devices.
Exchanged parameters are sent in organizationally specic TLVs in LLDP data units. For more information, refer to Link Layer
Discovery Protocol (LLDP). The following LLDP TLVs are supported for DCB parameter exchange:
PFC parameters PFC Conguration TLV and Application Priority Conguration TLV.
ETS parameters ETS Conguration TLV and ETS Recommendation TLV.
Data Center Bridging in a Trac Flow
The following gure shows how DCB handles a trac ow on an interface.
Figure 33. DCB PFC and ETS
Trac Handling
Enabling Data Center Bridging
DCB is automatically congured when you congure FCoE or iSCSI optimization.
Data center bridging supports converged enhanced Ethernet (CEE) in a data center network. DCB is disabled by default. It must be
enabled to support CEE.
• Priority-based ow control
• Enhanced transmission selection
• Data center bridging exchange protocol
• FCoE initialization protocol (FIP) snooping
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Data Center Bridging (DCB)