Administrator Guide

• Detects DCB mis-configuration in a peer device; that is, when DCB features are not compatibly
configured on a peer device and the local switch. Mis-configuration detection is feature-specific
because some DCB features support asymmetric configuration.
• Reconfigures a peer device with the DCB configuration from its configuration source if the peer device
is willing to accept configuration.
• Accepts the DCB configuration from a peer if a DCBx port is in “willing” mode to accept a peer’s DCB
settings and then internally propagates the received DCB configuration to its peer ports.
DCBx Port Roles
To enable the auto-configuration of DCBx-enabled ports and propagate DCB configurations learned from
peer DCBx devices internally to other switch ports, use the following DCBx port roles.
Auto-upstream The port advertises its own configuration to DCBx peers and receives its configuration
from DCBX peers (ToR or FCF device). The port also propagates its configuration to
other ports on the switch.
The first auto-upstream that is capable of receiving a peer configuration is elected as
the configuration source. The elected configuration source then internally propagates
the configuration to other auto-upstream and auto-downstream ports. A port that
receives an internally propagated configuration overwrites its local configuration with
the new parameter values.
When an auto-upstream port (besides the configuration source) receives and
overwrites its configuration with internally propagated information, one of the
following actions is taken:
• If the peer configuration received is compatible with the internally propagated
port configuration, the link with the DCBx peer is enabled.
• If the received peer configuration is not compatible with the currently configured
port configuration, the link with the DCBX peer port is disabled and a syslog
message for an incompatible configuration is generated. The network
administrator must then reconfigure the peer device so that it advertises a
compatible DCB configuration.
The configuration received from a DCBX peer or from an internally propagated
configuration is not stored in the switch’s running configuration.
On a DCBX port in an auto-upstream role, the PFC and application priority TLVs are
enabled. ETS recommend TLVs are disabled and ETS configuration TLVs are enabled.
Auto-downstream The port advertises its own configuration to DCBx peers but is not willing to receive
remote peer configuration. The port always accepts internally propagated
configurations from a configuration source. An auto-downstream port that receives an
internally propagated configuration overwrites its local configuration with the new
parameter values.
When an auto-downstream port receives and overwrites its configuration with
internally propagated information, one of the following actions is taken:
• If the peer configuration received is compatible with the internally propagated
port configuration, the link with the DCBx peer is enabled.
• If the received peer configuration is not compatible with the currently configured
port configuration, the link with the DCBX peer port is disabled and a syslog
message for an incompatible configuration is generated. The network
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