Chapter 49 Switching
GS1350 Series User’s Guide
353
GARP
GARP (Generic Attribute Registration Protocol) allows network switches to register and de-register
attribute values with other GARP participants within a bridged LAN. GARP is a protocol that provides a
generic mechanism for protocols that serve a more specific application, for example, GVRP
.
GARP Timers
Switches join VLANs by making a declaration. A declaration is made by issuing a Join message using
GARP. Declarations are withdrawn by issuing a Leave message. A Leave All message terminates all
registrations. GARP timers set declaration timeout values.
GVRP
GVRP (GARP VLAN Registration Protocol) is a registration protocol that defines a way for switches to
register necessary VLAN members on ports across the network. Enable this function to permit VLAN
groups beyond the local Switch.
Please refer to the following table for common IEEE 802.1Q VLAN terminology.
49.7.2.2 Port VLAN Trunking
Enable
VLAN Trunking
on a port to allow frames belonging to unknown VLAN groups to pass through
that port. This is useful if you want to set up VLAN groups on end devices without having to configure the
same VLAN groups on intermediary devices.
Refer to the following figure. Suppose you want to create VLAN groups 1 and 2 (V1 and V2) on devices
A and B. Without
VLAN Trunking
, you must configure VLAN groups 1 and 2 on all intermediary switches C,
D and E; otherwise they will drop frames with unknown VLAN group tags. However, with
VLAN Trunking
enabled on ports in each intermediary switch you only need to create VLAN groups in the end devices
Table 176 IEEE 802.1Q VLAN Terminology
VLAN PARAMETER
TERM
DESCRIPTION
VLAN Type
Permanent VLAN
This is a static VLAN created manually.
Dynamic VLAN
This is a VLAN configured by a GVRP registration or de-registration
process.
VLAN Administrative
Control
Registration Fixed
Fixed registration ports are permanent VLAN members.
Registration
Forbidden
Ports with registration forbidden are forbidden to join the specified
VLAN.
Normal Registration
Ports dynamically join a VLAN using GVRP.
VLAN Tag Control
Tagged
Ports belonging to the specified VLAN tag all outgoing frames
transmitted.
Untagged
Ports belonging to the specified VLAN do not tag all outgoing
frames transmitted.
VLAN Port
Port VID
This is the VLAN ID assigned to untagged frames that this port
received.
Acceptable Frame
Type
You may choose to accept both tagged and untagged incoming
frames, just tagged incoming frames or just untagged incoming
frames on a port.
Ingress filtering
If set, the Switch discards incoming frames for VLANs that do not
have this port as a member.