field dei enable vlan

Function

The field dei enable vlan command specifies the DEI capability for a range of VLANs on an interface.

The undo field dei enable vlan command cancels the function of specifying the DEI capability for a range of VLANs on an interface.

By default, the DEI capability is not enabled for the packets within a specified VLAN range on an interface.

Format

field dei enable vlan { { vlan-id1 [ to vlan-id2 ] } &<1-10> | all }

undo field dei enable vlan { { vlan-id1 [ to vlan-id2 ] } &<1-10> | all }

Parameters

Parameter	Description	Value
vlan-id1	Specifies the start VLAN ID.	The value is an integer that ranges from 1 to 4094.
to vlan-id2	Specifies the end VLAN ID.	The value is an integer ranging from 1 to 4094. The value of vlan-id2 must be greater than that of vlan-id1.
all	Enables or disables the DEI capability for all VLAN packets on the specified interface.	-

Parameter

Description

Value

vlan-id1

Specifies the start VLAN ID.

The value is an integer that ranges from 1 to 4094.

to vlan-id2

Specifies the end VLAN ID.

The value is an integer ranging from 1 to 4094. The value of vlan-id2 must be greater than that of vlan-id1.

all

Enables or disables the DEI capability for all VLAN packets on the specified interface.

Views

Interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
qos	write

Usage Guidelines

Usage Scenario

The field dei enable vlan 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 a VLAN 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 is supported only on a Layer 2 main interface and can be successfully configured only when the VLAN ID specified in this command falls within the VLAN ID range of the Layer 2 main interface.

Example

# Enable the packets carrying the VLAN ID of 2 with the DEI capability on GigabitEthernet 0/1/0.

<HUAWEI> system-view
[~HUAWEI] vlan 2
[*HUAWEI-vlan2] quit
[*HUAWEI] commit
[~HUAWEI] interface GigabitEthernet 0/1/0
[~HUAWEI-GigabitEthernet0/1/0] portswitch
[*HUAWEI-GigabitEthernet0/1/0] port default vlan 2
[*HUAWEI-GigabitEthernet0/1/0] field dei enable vlan 2