VLAN Configuration
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11
A QinQ tunnel port may receive either tagged or untagged packets. No matter how
many tags the incoming packet has, it is treated as tagged packet.
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 tunnel port are processed in
the following manner:
1. New SPVLAN tags are added to all incoming packets, no matter how many tags
they already have. The ingress process constructs and inserts the outer tag
(SPVLAN) into the packet based on the default VLAN ID and Tag Protocol
Identifier (TPID, that is, the ether-type of the tag). This outer tag is used for
learning and switching packets. The priority of the inner tag is copied to the outer
tag if it is a tagged or priority tagged packet.
2. After successful source and destination lookup, the ingress process sends the
packet to the switching process with two tags. If the incoming packet is
untagged, the outer tag is an SPVLAN tag, and the inner tag is a dummy tag
(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 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 a Tunnel 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
Summary of Contents for 8926EM
Page 6: ...ii ...
Page 34: ...Getting Started ...
Page 44: ...Introduction 1 10 1 ...
Page 62: ...Initial Configuration 2 18 2 ...
Page 64: ...Switch Management ...
Page 76: ...Configuring the Switch 3 12 3 ...
Page 118: ...Basic Management Tasks 4 42 4 ...
Page 164: ...User Authentication 6 28 6 ...
Page 176: ...Access Control Lists 7 12 7 ...
Page 284: ...Quality of Service 14 8 14 ...
Page 294: ...Multicast Filtering 15 10 15 ...
Page 300: ...Domain Name Service 16 6 16 ...
Page 310: ...Dynamic Host Configuration Protocol 17 10 17 ...
Page 320: ...Configuring Router Redundancy 18 10 18 ...
Page 344: ...IP Routing 19 24 19 ...
Page 356: ...Unicast Routing 20 12 20 Web Click Routing Protocol RIP Statistics Figure 20 5 RIP Statistics ...
Page 386: ...Unicast Routing 20 42 20 ...
Page 388: ...Command Line Interface ...
Page 400: ...Overview of the Command Line Interface 21 12 21 ...
Page 466: ...SNMP Commands 24 16 24 ...
Page 520: ...Access Control List Commands 26 18 26 ...
Page 546: ...Rate Limit Commands 30 2 30 ...
Page 612: ...VLAN Commands 34 24 34 ...
Page 626: ...Class of Service Commands 35 14 35 ...
Page 670: ...DHCP Commands 39 16 39 ...
Page 716: ...IP Interface Commands 41 36 41 ...
Page 768: ...IP Routing Commands 42 52 42 ...
Page 770: ...Appendices ...
Page 791: ......