dcb-dcbx (8) - Linux Manuals

dcb-dcbx: show / manipulate port DCBX (Data Center Bridging eXchange)


dcb-dcbx - show / manipulate port DCBX (Data Center Bridging eXchange)


dcb [ OPTIONS ] dcbx { COMMAND | help }

dcb dcbx show dev DEV

dcb dcbx set dev DEV [ host ] [ lld-managed ] [ cee ] [ ieee ] [ static ]


Data Center Bridging eXchange (DCBX) is a protocol used by DCB devices to exchange configuration information with directly connected peers. The Linux DCBX object is a 1-byte bitfield of flags that configure whether DCBX is implemented in the device or in the host, and which version of the protocol should be used. dcb dcbx is used to access the per-port Linux DCBX object.

There are two principal modes of operation: in host mode, DCBX protocol is implemented by the host LLDP agent, and the DCB interfaces are used to propagate the negotiate parameters to capable devices. In lld-managed mode, the configuration is handled by the device, and DCB interfaces are used for inspection of negotiated parameters, and can also be used to set initial parameters.


When used with dcb dcbx set, the following keywords enable the corresponding configuration. The keywords that are not mentioned on the command line are considered disabled. When used with show, each enabled feature is shown by its corresponding keyword.

lld-managed The device is in the host mode of operation and, respectively, the lld-managed mode of operation, as described above. In principle these two keywords are mutually exclusive, but dcb dcbx allows setting both and lets the driver handle it as appropriate.

ieee The device supports CEE (Converged Enhanced Ethernet) and, respecively, IEEE version of the DCB specification. Typically only one of these will be set, but dcb dcbx does not mandate this.

indicates the engine supports static configuration. No actual negotiation is performed, negotiated parameters are always the initial configuration.


Put the DCB engine into the "host" mode of operation, and use IEEE-standardized DCB interfaces:

# dcb dcbx set dev eth0 host ieee

Show what was set:

# dcb dcbx show dev eth0
host ieee


Exit status is 0 if command was successful or a positive integer upon failure.


Report any bugs to the Network Developers mailing list <netdev [at] vger.kernel.org> where the development and maintenance is primarily done. You do not have to be subscribed to the list to send a message there.


Petr Machata <me [at] pmachata.org>