dot1q termination vid

Function

The dot1q termination vid command sets the single VLAN ID for Dot1q termination on a sub-interface.

The undo dot1q termination vid command deletes the single VLAN ID for Dot1q termination on a sub-interface.

By default, the single VLAN ID for Dot1q termination is not set on a sub-interface.

Format

dot1q termination vid low-pe-vid [ to high-pe-vid ]

undo dot1q termination vid low-pe-vid [ to high-pe-vid ]

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this configuration.

Parameters

Parameter	Description	Value
low-pe-vid	Specifies the minimum value of the VLAN tag in user packets.	The value is an integer that ranges from 2 to 4094.
high-pe-vid	Specifies the maximum value of the VLAN tag in user packets. The value of high-pe-vid must be greater than or equal to the value of low-pe-vid.	The value is an integer that ranges from 2 to 4094.

Parameter

Description

Value

low-pe-vid

Specifies the minimum value of the VLAN tag in user packets.

The value is an integer that ranges from 2 to 4094.

high-pe-vid

Specifies the maximum value of the VLAN tag in user packets.

The value of high-pe-vid must be greater than or equal to the value of low-pe-vid.

The value is an integer that ranges from 2 to 4094.

Views

GE sub-interface view, XGE sub-interface view, 25GE sub-interface view, 40GE sub-interface view, 100GE sub-interface view, VE sub-interface view, Eth-Trunk sub-interface view, MultiGE sub-interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

Communication between VLANs
VLANs are widely used because they can separate Layer 2 packets. A physical LAN is divided into multiple logical broadcast domains. Hosts in the same VLAN can communicate with each other but the hosts of different VLANs cannot. The Layer 3 routing technology is used for communication between hosts of different VLANs in the following two methods:
- Through the VLANIF interface on the Layer 3 switch.
- Through the Layer 3 Ethernet interface on the Layer 3 switch.
  
  However, when a traditional Layer 3 Ethernet interface receives VLAN packets, the VLAN packets are discarded. To enable communication between hosts of different VLANs, you can create an Ethernet sub-interface on the Layer 3 Ethernet interface and enable QinQ termination on the sub-interface to remove the tag from the VLAN packet.
Communication between a LAN and a WAN

Most packets on a LAN have VLAN tags, but some WAN protocols such as ATM, FR, and PPP, cannot identify VLAN packets. To send a VLAN packet from LAN to WAN, the device records VLAN information in the packet, removes the VLAN tag, and forwards the packet.

Based on the number of tags, VLAN packets can be classified into Dot1q packets and QinQ packets. A Dot1q packet carries a single-layer VLAN tag and a QinQ packet carries a double-layer VLAN tag. Accordingly, there are two VLAN tag termination modes:

Dot1q termination, which terminates tags carried in Dot1q packets

To configure Dot1q termination, run the dot1q termination vid command.
QinQ termination, which terminates tags carried in QinQ packets.

To configure QinQ termination, run the qinq termination pe-vid ce-vid command in the sub-interface view.

After the dot1q termination vid command is run, the sub-interface for VLAN tag termination processes the packet in the following procedures:

The sub-interface removes the tag in the VLAN packet when receiving the packet and forwards the packet on Layer 3. The outbound interface determines whether the forwarded VLAN packet carries tags.
The sub-interface adds VLAN information to the packet and then sends the packet.

Precautions

The tag values of the user packet received by the sub-interface must be in the range of low-pe-vid to high-pe-vid specified in the command; otherwise, the packet is discarded.
The allowed VLANs on a sub-interface cannot be created in the system view or be displayed by the display command.
When the sub-interface is used for Layer 3 forwarding, it is recommended that there should be a maximum of 128 VLANs in the VLAN range. When there are more than 128 VLANs, IPv4 addresses can be configured but IPv6 addresses cannot be configured.
If the dot1q termination vid command is run more than once, all configurations take effect.

Example

# Set the encapsulation mode on XGigabitEthernet0/0/1.1 to Dot1q and allow the packets with the VLAN tag 100 to pass through.

<HUAWEI> system-view
[HUAWEI] vcmp role silent
[HUAWEI] interface xgigabitethernet 0/0/1
[HUAWEI-XGigabitEthernet0/0/1] port link-type hybrid
[HUAWEI-XGigabitEthernet0/0/1] quit
[HUAWEI] interface xgigabitethernet 0/0/1.1
[HUAWEI-XGigabitEthernet0/0/1.1] dot1q termination vid 100