VLAN C
ONFIGURATION
2-55Automatic VLAN Registration – GVRP (GARP VLAN Registration
Protocol) defines a system whereby the switch can a utomatically
learn the VLANs to which each endstation should be assigned. If
an endstation (or its network adapter) supports the IEEE 802.1Q
VLAN protocol, it can be configured to broadcast a message to
your network indicating the VLAN groups it wants to join. When
this switch receives these messages, it will automatically place the
receiving port in the specified VLANs, and then forward the
message to all other ports. When the message arrives at another
switch that supports GVRP, it will also place the receiving port in
the specified VLANs, and pass the message on to all other ports.
VLAN requirements are propagated in this way throughout the
network. This allows GVRP-compliant devices to be automatically
configured for VLAN groups based solely on endstation requests.
To implement GVRP in a network, first add the host devices to the
required VLANs (using the operating system or other application
software), so that these VLANs can be propagated onto the
network. For both the edge switches attached directly to these
hosts, and core switches in the network, enable GVRP on the links
between these devices. You should also determine security
boundaries in the network and disable GVRP on ports to prevent
advertisements being propagated, or forbid ports from joining
restricted VLANs.
Note: If you have host devices that do not support GVRP, you
must configure static VLANs for the switch ports connected
to these devices (as described in “Adding Static Members to
VLANs (VLAN Index)” on page 2-61). But you still need to
enable GVRP on these edge switches, as well as on the
core switches in the network.