Filter
Top Products
Intel® Blade Server Ethernet Switch Module IXM5414E 31
GARP VLAN Registration Protocol (GVRP)
GVRP (GARP VLAN Registration Protocol) is used to propagate VLAN membership information
throughout the network. GVRP is based on the Generic Attribute Registration Protocol (GARP),
which defines a method of propagating a defined attribute (i.e. VLAN membership) throughout the
network. GVRP allows both end stations and the switch module to issue and revoke declarations
relating to membership in VLANs. The Intel® Blade Server Ethernet Switch Module IXM5414E
complies with the specifications in IEEE 802.1D and IEEE 802.1Q.
End stations that participate in GVRP register VLAN membership via GARP Protocol Data Unit
(GPDU) messages. Networking devices that implement the GVRP protocol and enable GVRP then
process the GPDUs. The VLAN registration is made in the context of the port that receives the
GPDU. The switch module propagates this VLAN membership on all of its other ports in the active
topology. Thus, the end station's VLAN ID is propagated throughout the network.
GARP Multicast Registration Protocol (GMRP)
Networking devices use the GARP Multicast Registration Protocol to dynamically register (and de-
register) Group membership information with other networking devices attached to the same
segment and across all the bridged LAN devices that support Extended Filtering Services.
The operation of GMRP relies upon the services provided by the GARP. The information registered,
de-registered and disseminated via GMRP is in the following forms:
Group Membership Information
This indicates that there exists one or more GMRP participants which are members of a
particular Group, and carries the group MAC address(es) associated with this Group.
Registration of group membership information allows networking devices to be made aware
that frames destined for these group MAC address(es) should be forwarded in the direction
of registered members of the group. Forwarding of frames destined for the group MAC
address(es) occurs on ports on which such membership registration has been received.
Group Service Requirements Information
This indicates that one or more GMRP participants require Forward all Groups or Forward
Unregistered to be the default filtering behavior. Registration of group services requirement
information allows networking devices to be made aware that any of their ports that can
forward frames in the direction from which the group service requirement information has
been received should modify their default group behavior in accordance with the group
service requirement.
When the switch module receives GMRP PDUs it will update the multicast table with a new entry or
modify an existing entry with the new information. The switch module will forward multicast
packets through only those ports for which GMRP has created a group registration entry (for that
multicast address).
GMRP registrations are specific to a VLAN, which allows the Group filtering behavior for one
VLAN to be independent of the Group filtering behavior for other VLANs. The same ingress rules
are applied to GMRP PDUs as to other packets. Therefore:
• GMRP frames with no VLAN classification (i.e., untagged or priority-tagged GMRP frames)
are discarded if the Acceptable Frame Types parameter for the Port is set to Admit Only VLAN-
tagged frames. Otherwise, they are classified according to the PVID (Port VLAN ID) for the
Port.
• VLAN-tagged GMRP frames are classified according to the VID carried in the tag header.