Deployment Guide
Auto-Detection of the DCBx Version
The Aggregator operates in auto-detection mode so that 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 recongures 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).
• The peer times out.
• Multiple peers are detected on the link.
DCBx operations on a port are performed according to the auto-congured DCBx version, including fast and slow transmit timers and
message formats. If a DCBx frame with a dierent version is received, a syslog message is generated and the peer version is recorded in
the peer status table. If the frame cannot be processed, it is discarded and the discard counter is incremented.
DCBx Example
The following gure shows how DCBx is used on an Aggregator installed in a Dell PowerEdge FX2 server chassis in which servers are also
installed.
The Aggregator ports are numbered 1 to 12. Ports 1 to 8 are internal server-facing interfaces. Ports 9 to 12 are uplink ports. The uplink ports
on the base module (ports 9 to 12) are used for uplinks congured as DCBx auto-upstream ports. The Aggregator is connected to third-
party, top-of-rack (ToR) switches through the uplinks. The ToR switches are part of a Fibre Channel storage network.
The internal ports (ports 1 to 8) connected to the 10GbE backplane are congured as auto-downstream ports.
On the Aggregator, PFC and ETS use DCBx to exchange link-level conguration with DCBx peer devices.
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Data Center Bridging (DCB)