Configuring the ECN330-switch
298 1553-KDU 137 365 Uen D 2006-06-16
(8100 0000). If the incoming packet is tagged, the outer tag is an SPVLAN
tag, and the inner tag is a CVLAN tag.
3. After packet classification through the switching process, the packet is
written to memory with one tag (an outer tag) or with two tags (both an outer
tag and inner tag).
4. The ECN330-switch sends the packet to the proper egress port.
5. If the egress port is an untagged member of the SPVLAN, the outer tag will
be stripped. If it is a tagged member, the outgoing packets will have two tags.
Layer 2 Flow for Packets Coming into an Uplink Port
An uplink port receives one of the following packets:
• Untagged
• One tag (CVLAN or SPVLAN)
• Double tag (CVLAN + SPVLAN)
The ingress process does source and destination lookups. If both lookups are
successful, the ingress process writes the packet to memory. Then the egress
process transmits the packet. Packets entering a QinQ uplink port are
processed in the following manner:
1. If incoming packets are untagged, the PVID VLAN native tag is added.
2. If the ether-type of an incoming packet (single or double tagged) is not equal
to the TPID of the uplink port, the VLAN tag is determined to be a Customer
VLAN (CVLAN) tag. The uplink port’s PVID VLAN native tag is added to the
packet. This outer tag is used for learning and switching packets within the
service provider’s network. The TPID must be configured on a per port
basis, and the verification cannot be disabled.
3. If the ether-type of an incoming packet (single or double tagged) is equal to
the TPID of the uplink port, no new VLAN tag is added. If the uplink port is
not the member of the outer VLAN of the incoming packets, the packet will
be dropped when ingress filtering is enabled. If ingress filtering is not
enabled, the packet will still be forwarded. If the VLAN is not listed in the
VLAN table, the packet will be dropped.
4. After successful source and destination lookup, the packet is double tagged.
The ECN330-switch uses the TPID of 0x8100 to indicate that an incoming
packet is double-tagged. If the outer tag of an incoming double-tagged
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