INS_CWGE24MS2_REV–
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INSTALLATION AND OPERATION MANUAL
CWGE24MS2
TECH SUPPORT: 1.888.678.9427
GARP/GVRP
Introduction
GARP and GVRP are industry-standard protocols that are described in IEEE 802.1p. GVRP is a
GARP application that provides 802.1Q-compliant VLAN pruning and dynamic VLAN creation on
802.1Q trunk ports.
With GVRP, the switch can exchange VLAN configuration information with other GVRP switches,
prune unnecessary broadcast and unknown unicast traffic, and dynamically create and manage
VLANs on switches that are connected through 802.1Q trunk ports.
GVRP makes use of GID and GIP, which provide the common state machine descriptions and the
common information propagation mechanisms defined for use in GARP-based applications. GVRP
prunes trunk links so that only active VLANs will be sent across trunk connections. GVRP expects
to hear join messages from the switches before it will add a VLAN to the trunk. GVRP updates
and hold timers can be altered. GVRP ports run in various modes to control how they will prune
VLANs. GVRP can be configured to dynamically add and manage VLANS to the VLAN database
for trunking purposes.
In other words, GVRP allows the propagation of VLAN information from device to device. With
GVRP, a single switch is manually configured with all the desired VLANs for the network, and all
other switches on the network learn those VLANs dynamically. An end-node can be plugged
into any switch and be connected to that end-node’s desired VLAN. For end-nodes to make
use of GVRP, they need GVRP-aware Network Interface Cards (NICs). The GVRP-aware NIC is
configured with the desired VLAN or VLANs, then connected to a GVRP-enabled switch. The NIC
communicates with the switch, and VLAN connectivity is established between the NIC and switch.
Registration Mode:
» Normal:
The normal registration mode allows dynamic creation (if dynamic VLAN
creation is enabled), registration, and deregistration of VLANs on the trunk
port. Normal mode is the default.
» Forbidden:
The forbidden registration mode deregisters all VLANs (except VLAN 1) and
prevents any further VLAN creation or registration on the trunk port.
» Fixed:
The fixed registration mode allows manual creation and registration of VLANs,
prevents VLAN deregistration, and registers all known VLANs on other ports
on the trunk port. (Same as the static VLAN)
