Regulations For Double Vlans - D-Link xStack DGS-3426 User Manual

xStack DGS-3400 Series Layer 2 Gigabit Ethernet Managed Switch
In this example, the Service Provider Access Network switch (Provider edge switch) is the device creating and configuring
Double VLANs. Both CEVLANs (Customer VLANs) 10 and 11, are tagged with the SPVID 100 on the Service Provider Access
Network and therefore belong to one VLAN on the Service Provider's network, thus being a member of two VLANs. In this way,
the Customer can retain its normal VLAN and the Service Provider can congregate multiple Customer VLANs within one
SPVLAN, 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.
2. All ports must be configured as Access Ports or Uplink ports. Access ports can only be Ethernet ports while Uplink ports
must be Gigabit ports.
3. Provider Edge switches must allow frames of at least 1522 bytes or more, due to the addition of the SPVID tag.
4. Access Ports must be an un-tagged port of the service provider VLANs. Uplink Ports must be a tagged port of the service
provider VLANs.
5. The switch cannot have both double and normal VLANs co-existing. Once the change of VLAN is made, all Access
Control lists are cleared and must be reconfigured.
6. Once Double VLANs are enabled, GVRP must be disabled.
7. All packets sent from the CPU to the Access ports must be untagged.
8. The following functions will not operate when the switch is in Double VLAN mode:
•
Guest VLANs
•
Web-based Access Control
•
IP Multicast Routing
•
GVRP
•
All Regular 802.1Q VLAN functions
Figure 7- 8. Double VLAN Example
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