3Com Switch 7750 Configuration Guide

20
SELECTIVE QINQ CONFIGURATION
Selective QinQ
Overview
Selective QinQ
Implementation
On a Switch 7750 Ethernet switch, selective QinQ can be implemented in the
following ways.
1 Enabling QinQ on ports
In this type of implementations, QinQ is enabled on ports and a received packet is
tagged with the default VLAN tag of the receiving port no matter whether or not
the packet already carries a VLAN tag. If the packet already carries a VLAN tag, the
packet becomes a dual-tagged packet. Otherwise, the packet becomes a packet
carrying the default VLAN tag of the port.
2 Configuring VLAN mapping
In this type of implementations, packets transmitted through the same port are
tagged with outer VLAN tags according to the VLAN ID they carry. This is achieved
by using the corresponding commands.
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For Switch 7750 Ethernet switches, the selective QinQ feature can also be
achieved through using ACL and QoS together. Refer to “Configuring Traffic-Based
Selective QinQ” on page 679 for related configurations.
Outer Tag Replacement Switch 7750s support the outer VLAN tag replacement function. You can specify
one or more inner VLAN tags and an outer VLAN tag as a match rule. When
receiving a double-tagged packet that matches the rule, the switch will replace the
outer VLAN tag of the packet with a specified VLAN tag so that the packet will be
forwarded as per the new outer VLAN tag, with the inner VLAN tag unchanged.
Selective QinQ
Configuration
Configuring Selective
QinQ
Configuration Prerequisites
■ Enable QinQ in Ethernet port view.
■ Set the VLANs whose packets are permitted the port.