Dell POWEREDGE M1000E - Manual (Page 71)

Switch Features 71
GARP and GVRP Support
The switch supports the configuration of Generic Attribute Registration
Protocol (GARP) timers GARP VLAN Registration Protocol (GVRP) relies on
the services provided by GARP to provide IEEE 802.1Q-compliant VLAN
pruning and dynamic VLAN creation on 802.1Q trunk ports. When GVRP is
enabled, the switch registers and propagates VLAN membership on all ports
that are part of the active spanning tree protocol topology.
For information about configuring GARP timers see "Configuring L2
Multicast Features" on page 713.
Voice VLAN
The Voice VLAN feature enables switch ports to carry voice traffic with
defined priority. The priority level enables the separation of voice and data
traffic coming onto the port.
Guest VLAN
The Guest VLAN feature allows a switch to provide a distinguished service to
unauthenticated users. This feature provides a mechanism to allow visitors
and contractors to have network access to reach external network with no
ability to browse information on the internal LAN.
For information about configuring the Guest VLAN see "Configuring 802.1X
and Port-Based Security" on page 509.
Double VLANs
The Double VLAN feature (IEEE 802.1QinQ) allows the use of a second tag
on network traffic. The additional tag helps differentiate between customers
in the Metropolitan Area Networks (MAN) while preserving individual
customer’s VLAN identification when they enter their own 802.1Q domain.