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ManualsBrandsDell ManualsConverged InfrastructureQLogic Family of Adapters
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14–Data Center Bridging
Configuring DCB
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Data Center Bridging Exchange (DCBX)
Data center bridging exchange (DCBX) is a discovery and capability exchange
protocol that is used for conveying capabilities and configuration of ETS and PFC
between link partners to ensure consistent configuration across the network
fabric. In order for two devices to exchange information, one device must be
willing to adopt network configuration from the other device. For example, if a
C-NIC is configured to willingly adopt ETS and PFC configuration information from
a connected switch, and the switch acknowledges the C-NIC’s willingness, the
switch will send the C-NIC the recommended ETS and PFC parameter settings.
The DCBX protocol uses the link level discovery protocol (LLDP) to exchange
PFC and ETS configurations between link partners.
Configuring DCB
By default, DCB is enabled on BCM57712/578xx DCB-compatible C-NICs. DCB
configuration is rarely required, as the default configuration should satisfy most
scenarios. DCB parameters can be configured through QCS CLI. For more
information on QCS CLI, see the User’s Guide, QLogic Control Suite CLI.
DCB Conditions
The following conditions allow DCB technology to function on the network:
If DCB is enabled on the interface, DCBX is automatically enabled and
carried out automatically when a link is established.
If DCBX fails to synchronize with a compatible peer, the adapter will
automatically fall back to default NIC behavior (no priority tagging, no PFC,
no ETS).
By default, the port will advertise itself as willing, and as such, will accept all
DCB settings as advertised by the switch.
If PFC is operational, PFC settings supersede link level flow control settings.
If PFC is not operational, link level flow control settings prevail.
NOTE
FCoE operation depends on successful VLAN discovery. All switches that
support FCoE support VLAN discovery, but some switches may require
specific configuration. Refer to the switch configuration guides for
information on how to configure a port for successful VLAN discovery.