DELL 8132 ユーザーズマニュアル

Data Center Bridging Commands

the DCBX conforms to all aspects of the legacy standards to the degree 

necessary to support interoperability with a wide variety of FCoE capable 

switches.
The main objective of DCBX is to perform the following operations:

• Discovery of DCB capability in a peer

DCBX is used to learn about the capabilities of the peer device. It is a 

means to determine if the peer device supports a particular feature such as 

PFC. 

• DCB feature misconfiguration detection

DCBX can be used to detect misconfiguration of a feature between the 

peers on a link. Misconfiguration detection is feature-specific because 

some features may allow asymmetric configuration. 

• Peer configuration of DCB features

DCBX can be used by a device to perform configuration of DCB features 

in its peer device if the peer device is willing to accept configuration.

The PowerConnect switch automatically detects if a peer is operating with 

either of the two CEE DCBX versions or the IEEE standard DCBX version. 

This is the default mode. DCBX can also be configured to manually select 

one of the legacy versions or IEEE standard mode. In auto-detect mode, the 

switch starts operating in IEEE DCBX mode on a port and if it detects a 

legacy DCBX device based on the OUI of the organization TLV, then the 

switch changes its DCBX mode on that port to support the version detected. 

There is no time out mechanism to move back to IEEE mode. Once the 

DCBX peer times out, multiple peers are detected, the link is reset (link 

down/up) or as commanded by the operator, DCBX resets its operational 

mode to IEEE.
The interaction between DCBX component and other components remains 

the same irrespective of the operational mode it is executing. For instance, 

DCBX component interacts with PFC to get needed information to pack the 

TLVs to be sent out on the interface. Based on the operational control mode 

of the port, DCBX packs it in the proper frame format.

2CSPC4.X8100-SWUM102.book  Page 873  Friday, March 15, 2013  8:56 AM