Specifications

VLANs
Extreme Networks EAS 100-24t Switch Software Manual
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ports 1, 2, 3 and 4 and VLAN 2 members to ports 1, 5, 6 and 7, Port 1 will belong to two VLAN groups.
Ports 8, 9 and 10 are not configured to any VLAN group. This means ports 8, 9 and 10 are in the same
VLAN group.
VLAN and Trunk Groups
The members of a trunk group have the same VLAN setting. Any VLAN setting on the members of a
trunk group will apply to the other member ports.
NOTE
In order to use VLAN segmentation in conjunction with port trunk groups, you can first set the port trunk
group(s), and then you may configure VLAN settings. If you wish to change the port trunk grouping with VLANs
already in place, you will not need to reconfigure the VLAN settings after changing the port trunk group settings.
VLAN settings will automatically change in conjunction with the change of the port trunk group settings.
Q-in-Q VLANs
Q-in-Q VLANs (also sometimes referred to as double VLANs) allow network providers to expand their
VLAN configurations to place customer VLANs within a larger inclusive VLAN, which adds a new
layer to the VLAN configuration. This basically lets large ISP's create L2 Virtual Private Networks and
also create transparent LANs for their customers, which will connect two or more customer LAN points
without over-complicating configurations on the client's side. Not only will over-complication be
avoided, but also now the administrator has over 4000 VLANs in which over 4000 VLANs can be
placed, therefore greatly expanding the VLAN network and enabling greater support of customers
utilizing multiple VLANs on the network.
Q-in-Q 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 Q-in-Q VLAN tagged packet:
Regulations for Q-in-Q VLANs
Some rules and regulations apply with the implementation of the Q-in-Q 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 Q-in-Q and normal VLANs co-existing. Once the change of VLAN is
made, all Access Control lists are cleared and must be reconfigured.
Destinatio
n Address
Source
Address
SPVLAN (TPID + Service
Provider VLAN Tag)
802.1Q CEVLAN Tag
(TPID + Customer
VLAN Tag)
Ether
Type Payload