Field Description
Value
Attribute
Consists of an attribute length, an
attribute event, and an attribute
value
––
Attribute length
Length of an attribute, inclusive of
the attribute length field
2 to 255 (in bytes)
Attribute event
Event that the attribute describes
•
0x00: LeaveAll event
•
0x01: JoinEmpty event
•
0x02: JoinIn event
•
0x03: LeaveEmpty event
•
0x04: LeaveIn event
•
0x05: Empty event
Attribute value
Attribute value
VLAN ID for GVRP
If the value of the attribute event
field is 0x00 (LeaveAll event), the
attribute value field is invalid.
The destination MAC addresses of GARP messages are multicast MAC addresses, and vary with GARP
applications. For example, the destination MAC address of GVRP is 01-80-C2-00-00-21. A switch
distributes GARP messages to different GARP applications according to the destination MAC addresses
carried in GARP messages.
GVRP
GVRP overview
As a GARP application, GVRP enables a switch to propagate local VLAN registration information to
other participant devices, and to dynamically update its local database with the VLAN registration
information from other devices, including active VLAN members and the ports through which they can be
reached. This ensures that all GVRP participants on a bridged LAN maintain the same VLAN registration
information. The VLAN registration information propagated by GVRP includes both manually configured
local static entries and dynamic entries from other devices.
GVRP registration modes
Manually created VLANs are called “static VLANs,” and VLANs created by GVRP are called “dynamic
VLANs.” GVRP provides the following registration modes on a port: normal, fixed, and forbidden. The
different registration modes determine how a port handles static and dynamic VLANs.
•
Normal: Allows dynamic creation, registration, and deregistration of VLANs on the trunk port.
•
Fixed: Allows manual creation and registration of VLANs, prevents VLAN deregistration, and
registers all known VLANs on other ports on the trunk port.
•
Forbidden: Deregisters all VLANs (except VLAN 1) and prevents any further VLAN creation or
registration on the trunk port.
Protocols and standards
•
IEEE 802.1Q,
Virtual Bridged Local Area Networks
GVRP configuration task list
Complete these tasks to configure GVRP:
128