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flowcontrol rx on tx off
dcb-map DCB_MAP_PFC_OFF
!
protocol lldp
advertise management-tlv management-address system-name
dcbx port-role auto-downstream
no shutdown
Dell#
When DCB is Enabled When an interface receives a DCBx protocol packet, it automatically enables DCB and disables link-level
flow control. The dcb-map and flow control configurations are removed as shown in the following example.
show interfaces Command Example: DCB enabled and Flow Control disabled
Dell#show running-config interface te 0/3
!
interface TenGigabitEthernet 0/3
mtu 12000
portmode hybrid
switchport
auto vlan
!
protocol lldp
advertise management-tlv management-address system-name
dcbx port-role auto-downstream
no shutdown
Dell#
When no DCBx TLVs are received on a DCB-enabled interface for 180 seconds, DCB is automatically disabled and flow control is
re-enabled.
Lossless Traffic Handling In auto-DCB-enable mode, Aggregator ports operate with the auto-detection of DCBx traffic. At
any moment, some ports may operate with link-level flow control while others operate with DCB-based PFC enabled.
As a result, lossless traffic is ensured only if traffic ingresses on a PFC-enabled port and egresses on another PFC-enabled port.
Lossless traffic is not guaranteed when it is transmitted on a PFC-enabled port and received on a link-level flow control-enabled
port, or transmitted on a link-level flow control-enabled port and received on a PFC-enabled port.
Enabling DCB on Next Reload To configure the Aggregator so that all interfaces come up with DCB enabled and flow control
disabled, use the dcb enable on-next-reload command. Internal PFC buffers are automatically configured.
1. Globally enable DCB on all interfaces after next switch reload.
CONFIGURATION mode
dcb enable on-next-reload
To reconfigure the Aggregator so that all interfaces come up with DCB disabled and link-level flow control enabled, use the no
dcb enable on-next-reload command. PFC buffer memory is automatically freed.
Enabling Auto-DCB-Enable Mode on Next Reload To configure the Aggregator so that all interfaces come up in auto-DCB-
enable mode with DCB disabled and flow control enabled, use the dcb enable aut-detect on-next-reload command.
1. Globally enable auto-detection of DCBx and auto-enabling of DCB on all interfaces after switch reload.
CONFIGURATION mode
dcb enable auto-detect on-next-reload
Enabling DCB To configure the Aggregator so that all interfaces are DCB enabled and flow control disabled, use the dcb
enable command.
Disabling DCB To configure the Aggregator so that all interfaces are DCB disabled and flow 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
Data Center Bridging (DCB)
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