Reference Guide

Enabling Auto-DCB-Enable Mode on Next Reload To congure the Aggregator so that all interfaces come up in auto-DCB-enable

mode with DCB disabled and ow control enabled, use the dcb enable aut-detect on-next-reload command.

Task Command Command Mode

Globally enable auto-detection of DCBx

and auto-enabling of DCB on all interfaces

after switch reload.

dcb enable auto-detect on-next-reload CONFIGURATION

Enabling DCB To congure the Aggregator so that all interfaces are DCB enabled and ow control disabled, use the dcb enable

command.

Disabling DCB To congure the Aggregator so that all interfaces are DCB disabled and ow control enabled, use the no dcb

enable command.

dcb enable auto-detect on-next-reload Command Example

Dell#dcb enable auto-detect on-next-reload

Conguring Priority-Based Flow Control

PFC provides a ow control mechanism based on the 802.1p priorities in converged Ethernet trac received on an interface and is

enabled by default when you enable DCB.

As an enhancement to the existing Ethernet pause mechanism, PFC stops trac transmission for specied priorities (Class of

Service (CoS) values) without impacting other priority classes. Dierent trac types are assigned to dierent priority classes.

When trac congestion occurs, PFC sends a pause frame to a peer device with the CoS priority values of the trac that is to be

stopped. Data Center Bridging Exchange protocol (DCBx) provides the link-level exchange of PFC parameters between peer

devices. PFC allows network administrators to create zero-loss links for Storage Area Network (SAN) trac that requires no-drop

service, while retaining packet-drop congestion management for Local Area Network (LAN) trac.

To ensure complete no-drop service, apply the same dcb-map on all PFC and ETS enabled interfaces.

1. Create a DCB map to apply priority based ow control or enhanced transmission selection for specied priority groups and

priorities.

CONFIGURATION mode

dcb-map map-name

The maximum is 32 alphanumeric characters.

2. Congure the priority group with PGID, bandwidth percentage or strict priority for ETS and PFC mode.

DCB-MAP mode

priority-group pg_num [bandwidth percentage | strict-priority] pfc [on | off]

pg_num range is from 0 to 7.

bandwidth percentage range is from 1 to 100.

Either strict-priority or bandwidth percentage can be set for ETS on the priority group.

PFC can either be enabled or disabled for the priority group.

3. Congure the priorities to priority group.

DCB-MAP mode

priority-pgid <pgid> <pgid> <pgid> <pgid> <pgid> <pgid> <pgid> <pgid>

pgid range is from 0 to 7.

Data Center Bridging (DCB)