dei enable
Function
The dei enable command maps the drop eligible indicator (DEI) field in a VLAN tag to the drop priority.
The undo dei enable command cancels the configuration of the DEI field in a VLAN tag as the drop priority.
By default, the DEI field in a VLAN tag is not used as the drop priority.
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735-S-I, S5735S-S, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this command.
Views
GE interface view, XGE interface view, MultiGE interface view, 25GE interface view, 40GE interface view, 100GE interface view, Eth-Trunk interface view, Eth-Trunk member interface view, port group view
Usage Guidelines
Scenario
The DEI is also called the Canonical Format Indicator (CFI) field in a VLAN tag and its value is 0 or 1. The DEI field in a VLAN tag is used as the drop priority of packets in certain situations. When the rate of packets on certain devices exceeds the CIR value, the DEI field is set to 1. In this case, the drop priority of the packets is high. When congestion occurs, subsequent devices first discard the packets whose DEI field is 1.
Precautions
After the dei enable command is run, the DEI field in the VLAN tag is mapped to the drop priority:
- The DEI field in the VLAN tag is mapped to the drop priority (packet color) on the inbound interface as follows:
- When the DEI field is 0, packets are colored green.
- When the DEI field is 1, packets are colored yellow.
- The drop priority is mapped to the DEI field on the outbound interface as follows:
- Green and yellow packets correspond to DEI 0.
- Red packets correspond to DEI 1.
The dei enable command cannot be configured on both an Eth-Trunk and its member interfaces.
To configure the DEI field in a VLAN tag as the drop priority on multiple interfaces, perform the configuration on a port group to reduce the workload.