Dell PowerConnect 8024 User Configuration Manual page 813

local configuration and utilize the internally propagated information. Auto-
downstream ports propagate PFC, ETS, and application priority information
received from the configuration source.
In the Configuration Source role, the port has been manually selected to be
the configuration source. Configuration received over this port is propagated
to the other auto-configuration ports, however, no automatic election of a
new configuration source port is allowed. Events that cause selection of a new
configuration source are ignored. The configuration received over the
configuration source port is maintained until cleared by the operator (set the
port to the manual role).
Configuration Source Port Selection Process
When an auto-upstream or auto-downstream port receives a configuration
from a peer, the DCBX client first checks if there is an active configuration
source. If there is a configuration source already selected, the received
configuration is checked against the local port operational values as received
from the configuration source, and if compatible, the client marks the port as
operationally enabled. If the configuration received from the peer is
determined to not be compatible, a message is logged, an error counter is
incremented and the DCBX clients become operationally disabled on the
port. Operationally disabled means that FIP snooping and PFC will not
operate over the port. The port continues to keep link up and exchanges
DCBX packets. If a compatible configuration is later received, the DCBX
clients will become operationally enabled.
If there is no configuration source, a port may elect itself as the configuration
source on a first-come, first-serve basis from the set of eligible ports. A port is
eligible to become the configuration source if the following conditions are
true:
• No other port is the configuration source.
• The port role is auto-upstream.
• The port is enabled with link up and DCBX enabled.
• The port has negotiated a DCBX relationship with the partner.
• The switch is capable of supporting the received configuration values,
either directly or by translating the values into an equivalent configuration.
Whether or not the peer configuration is compatible with the configured
values is NOT considered.
Configuring Data Center Features
813