Propagation Of Dcb Information; Auto-Detection And Manual Configuration Of The Dcbx Version - Dell Force10 S4810P Configuration Manual

• The port is enabled with link up and DCBx enabled.
• The port has performed a DCBx exchange with a DCBx peer.
• The switch is capable of supporting the received DCB configuration values through either a
symmetric or asymmetric parameter exchange.
A newly elected configuration source propagates configuration changes received from a peer to the other
auto-configuration ports. Ports receiving auto-configuration information from the configuration source
ignore their current settings and use the configuration source information.

Propagation of DCB Information

When an auto-upstream or auto-downstream port receives a DCB configuration from a peer, the port acts
as a DCBx client and checks if a DCBx configuration source exists on the switch.
• If a configuration source is found, the received configuration is checked against the currently
configured values that are internally propagated by the configuration source. If the local configuration
is compatible with the received configuration, the port is enabled for DCBx operation and
synchronization.
• If the configuration received from the peer is not compatible with the internally propagated
configuration used by the configuration source, the port is disabled as a client for DCBx operation and
synchronization and a syslog error message is generated. The port keeps the peer link up and continues
to exchange DCBx packets. If a compatible configuration is later received from the peer, the port is
enabled for DCBx operation.
Note: DCB configurations internally propagated from a configuration source do not overwrite the
configuration on a DCBx port in a manual role.
When a configuration source is elected, all auto-upstream ports other than the configuration source are
marked as willing disabled. The internally propagated DCB configuration is refreshed on all
auto-configuration ports and each port may begin configuration negotiation with a DCBx peer again.
Auto-Detection and Manual Configuration of the DCBx
Version
When operating in Auto-Detection mode (
Procedure), a DCBx port automatically detects the DCBx version on a peer port. Legacy CIN and CEE
versions are supported in addition to the standard IEEE version 2.5 DCBx.
A DCBx port detects a peer version after receiving a valid frame for that version. The local DCBx port
reconfigures to operate with the peer version and maintains the peer version on the link until one of the
following conditions occurs:
• The switch reboots.
• The link is reset (goes down and up).
• User-configured CLI commands require the version negotiation to restart.
• The peer times out.
• Multiple peers are detected on the link.
command in the
DCBx version auto
DCBx Configuration
Data Center Bridging (DCB) | 325