Regulations For Double Vlans - D-Link xStack DES-3528 series User Manual

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xStack DES-3528/DES-3552 Series Layer 2 Stackable Fast Ethernet Managed Switch User Manual
now has over 4000 VLANs that can be placed, and this greatly expands the VLAN network and enables greater
support of customers utilizing multiple VLANs on the network.
Double VLANs are basically VLAN tags placed within existing IEEE 802.1Q VLANs which we will call SPVIDs (Service
Provider VLAN IDs). These VLANs are marked by a TPID (Tagged Protocol ID), configured in hex form to be
encapsulated within the VLAN tag of the packet. This identifies the packet as double-tagged and segregates it from
other VLANs on the network, therefore creating a hierarchy of VLANs within a single packet.
Here is an example Double VLAN tagged packet.
Destination
Address
Consider the example below:
In this example, the Service Provider Access Network switch (Provider edge switch) is the device creating and
configuring Double VLANs with different SPVIDs for specific customers (say Customer A and Customer B). Both
CEVLANs (Customer VLANs), CEVLAN 10 are tagged with the SPVID 100 (for Customer A) and SPVID 200 (for
Customer B) on the Service Provider Access Network, thus being a member of two VLANs on the Service Provider's
network. In this way, the Customer can retain their normal VLAN ID's and the Service Provider can seperate multiple
Customer VLANs using SPVLANs, thus greatly regulating traffic and routing on the Service Provider switch. This
information is then routed to the Service Provider's main network and regarded there as one VLAN, with one set of
protocols and one routing behavior.

Regulations for Double VLANs

Some rules and regulations apply with the implementation of the Double VLAN procedure.
1. All ports must be configured for the SPVID and its corresponding TPID on the Service Provider's edge switch.
Source SPVLAN ( TPID +
Address Service P rovider
VLAN Tag)
Figure 3 - 5 Double VLAN Example
802.1Q C EVLAN T ag
(TPID + Customer VLAN
Tag)
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Ether Payload
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