field dei enable

Function

The field dei enable command specifies the DEI capability for an interface.

The undo field dei enable command cancels the function of specifying the DEI capability for an interface.

By default, the DEI capability is not enabled for the packets on an interface.

Format

field dei enable

undo field dei enable

Parameters

None

Views

FlexE sub-interface view, Sub-interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
qos	write

Usage Guidelines

Usage Scenario

The field dei enable command sets the capability of an interface to recognize the drop precedence of 802.1p packets. After this capability is assigned on an interface, the device can then identify the drop precedence of packets according to the CFI of the packet in the inbound or outbound direction of the interface. The packets with higher drop precedence are dropped first when a network is congested.

The Drop Eligible Indicator (DEI) and CFI share the same bit. If DEI is disabled, this bit is occupied by the CFI.

The DEI function takes effect only after simple traffic classification is configured and trust priority of 802.1p . After you enable DEI for an interface and configure simple traffic classification, packets enter queues based on CoSs and are marked with different colors based on the values of their CFI fields.

When DEI is enabled, if the DEI value is 1, the packet is marked yellow; if the DEI value is 0, the packet is marked green.
If DEI is disabled, the device maps the external priority of a packet to the internal priority based on the 802.1p value, regardless of whether the DEI value is 0 or 1. By default, all packets are marked green.

Prerequisites

The DEI function takes effect only when the trust upstream command is run to configure BA classification and the trust 8021p command is run to trust 802.1p values of packets.

Precautions

This command can be configured only on Ethernet and trunk sub-interfaces. If this command is configured on global VE or VE sub-interfaces with dot1q VLAN tag termination, the configuration fails.

Example

# Enable the DEI capability on GigabitEthernet 0/1/0.1.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet 0/1/0.1
[~HUAWEI-GigabitEthernet0/1/0.1] field dei enable