Vlan Termination Configuration; Vlan Termination Types; Application Scenarios - HP A6600 Configuration Manual

VLAN termination configuration

The SAP cards support the feature only when they work in Layer 2 mode.
VLAN termination refers to the following packet processing procedure:
A port receives a VLAN-tagged packet, removes its VLAN tags and then forwards it via Layer 3 or
•
processes it in other ways. Whether the packet is tagged before being sent out depends on the port
configuration.
• Before sending a packet, the port adds related VLAN information to it.

VLAN termination types

Based on the number of tags a VLAN-tagged packet carries, the VLAN-tagged packets falls into:
• Dot1q packet (also known as an 802.1q packet), which carries a single VLAN tag
• QinQ packet, which carries double VLAN tags
Accordingly, VLAN termination falls into two types:
Dot1q termination: Terminates Dot1q packets and removes a Dot1q packet's single VLAN tag.
•
QinQ termination: Terminates QinQ packets and removes a QinQ packet's inner and outer VLAN
•
tags.
A main interface cannot process VLAN-tagged packets, but you can create subinterfaces for it to process
VLAN-tagged packets.
A subinterface receives and sends only VLAN-tagged packets.

Application scenarios

VLAN termination is mainly used for the following purposes:
• Inter-VLAN communication
• LAN-WAN communication
Inter-VLAN communication
VLAN technology is widely used to isolate Layer 2 packets. It divides a LAN into multiple VLANs with
each being a broadcast domain. Hosts within a VLAN can communicate with each other directly,
whereas hosts in different VLANs are isolated at Layer 2. To allow different VLANs to communicate, you
must use Layer 3 routing. Configure the following methods to implement VLAN communication:
Configuring VLAN interfaces on Layer 3 switches, as shown in
•
Configuring Layer 3 Ethernet subinterfaces on routers, as shown in
•
In both Figure 54
specify Host A's gateway IP address as 1.1.1.1/24 and Host B's gateway IP address as 1.1.2.1/24,
Host A and Host B can communicate at Layer 3 through VLAN interfaces or Layer 3 Ethernet
subinterfaces.
and Figure 55, Host A belongs to VLAN 2, and Host B belongs to VLAN 3. After you
Figure
160
54.
Figure 55.