Dell S4048T, Configuration Manual

Page: 412 / 1277

GARP VLAN Registration Protocol
(GVRP)
The generic attribute registration protocol (GARP) VLAN registration protocol (GVRP), defined by the IEEE
802.1q specification, is a Layer 2 network protocol that provides for automatic VLAN configuration of
switches. GVRP-compliant switches use GARP to register and de-register attribute values, such as VLAN IDs,
with each other.
Typical virtual local area network (VLAN) implementation involves manually configuring each Layer 2 switch
that participates in a given VLAN. GVRP, defined by the IEEE 802.1q specification, is a Layer 2 network
protocol that provides for automatic VLAN configuration of switches. GVRP-compliant switches use GARP to
register and de-register attribute values, such as VLAN IDs, with each other.
GVRP exchanges network VLAN information to allow switches to dynamically forward frames for one or more
VLANs. Therefore, GVRP spreads this information and configures the needed VLANs on any additional
switches in the network. Data propagates via the exchange of GVRP protocol data units (PDUs).
The purpose of GVRP is to simplify (but not eliminate) static configuration. The idea is to configure switches at
the edge and have the information dynamically propagate into the core. As such, the edge ports must still be
statically configured with VLAN membership information, and they do not run GVRP. It is this information that
is propagated to create dynamic VLAN membership in the core of the network.
Important Points to Remember
• GVRP propagates VLAN membership throughout a network. GVRP allows end stations and switches to
issue and revoke declarations relating to VLAN membership.
• VLAN registration is made in the context of the port that receives the GARP PDU and is propagated to
the other active ports.
• GVRP is disabled by default; enable GVRP for the switch and then for individual ports.
• Dynamic VLANs are aged out after the LeaveAll timer expires three times without receipt of a Join
message. To display status, use the
show gvrp statistics {interface interface | summary}
command.
• If spanning tree and GVRP are both required, implement the rapid spanning tree protocol (RSTP). The
device does not support enabling GVRP and MSTP at the same time.
Dell(conf)#protocol spanning-tree pvst
Dell(conf-pvst)#no disable
% Error: GVRP running. Cannot enable PVST.
.........
Dell(conf)#protocol spanning-tree mstp
Dell(conf-mstp)#no disable
% Error: GVRP running. Cannot enable MSTP.
.........
19
GARP VLAN Registration Protocol (GVRP) 412