No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

AR500, AR510, and AR530 V200R007 CLI-based Configuration Guide - Ethernet Switching

This document describes the configuration of Ethernet services, including configuring transparent bridge, MAC table, link aggregation, VLANs, STP/RSTP/MSTP, and so on.The document provides the configuration procedures and configuration examples to illustrate the service configuration methods and application scenario.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Introduction to VLAN Termination

Introduction to VLAN Termination

This section describes the definition, classification, and purpose of VLAN termination.

Definition

VLAN termination is a VLAN tag processing mechanism. After VLAN termination is enabled on a device, the device identifies VLAN tags in received packets, removes single or double tags from the packets, and then forwards packets at Layer 3 or takes other actions. These VLAN tags are only useful before termination, and are not used in Layer 3 forwarding or other processing.

A device with VLAN termination enabled processes incoming and outgoing packets as follows:
  • Removes VLAN tags from the packets received on interfaces, and then forwards the packets at Layer 3 or takes other actions.
  • Adds VLAN tags to the packets that will be sent out through interfaces.

Classification

Depending on the modes in which VLAN tagged packets are processed, VLAN termination has the following sub-functions:

  • Dot1q termination: removes the outer VLAN tag from the received single-tagged or double-tagged packets, and adds a VLAN tag to the packets to be sent by an interface.
  • QinQ termination: removes double VLAN tags from the received double-tagged packets, and adds double VLAN tags to the packets to be sent by an interface.

Generally, VLAN termination is configured on sub-interfaces. A sub-interface that terminates single tags in packets is called a Dot1q termination sub-interface, and a sub-interface that terminates double tags in packets is called a QinQ termination sub-interface.

NOTE:
Dot1q and QinQ VLAN tag termination sub-interfaces do not support transparent transmission of packets that do not contain a VLAN tag, and discard received packets that do not contain a VLAN tag.

Purpose

After VLANs are assigned on a network, hosts in the same VLAN can communicate with each other at Layer 2, whereas hosts in different VLANs cannot. You can use VLANIF interfaces on a router to implement inter-VLAN Layer 3 connectivity. As shown in Figure 5-1, when a router uses only one Layer 3 Ethernet interface to connect to users or a network, this interface needs to transmit packets from multiple VLANs. A VLANIF interface cannot provide this function. You can virtualize a Layer 3 Ethernet interface into multiple logical sub-interfaces. The Layer 3 Ethernet interface is the main interface for the logical sub-interfaces.

Figure 5-1  Networking of configuring sub-interfaces to implement interworking

By default, a Layer 3 Ethernet sub-interface treats received VLAN packets as invalid packets and discards them; therefore, VLAN termination needs to be configured on the Layer 3 Ethernet sub-interface so that the sub-interface can remove VLAN tags from packets.

Translation
Download
Updated: 2019-05-25

Document ID: EDOC1000097279

Views: 19660

Downloads: 64

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Share
Previous Next