Intel BLADE SERVER IXM5414E - Manuale (Pagina 56)

Switch Management and Operating Concepts 33
group with the matching protocol, the packet will be assigned the group’s VID, otherwise it will be
dropped. If no VID has been configured for the group, the PVID will be used.
Static MAC filtering
Static MAC Filtering allows you to add a small number (in the order of hundreds) of unicast or
multicast MAC addresses directly to the forwarding database. Associated with each Static MAC
address is a set of destination ports and VLAN information.
Any packet with a particular Static MAC Address in a particular VLAN is admitted only if the
ingress port is in the set of source ports, otherwise the packet is dropped. On the egress side the
packet, if admitted, is sent out of all the ports that are in the set of destination ports.
Upon ingress, each packet's destination MAC address is compared against the forwarding database.
If the address is not in the table, the packet is flooded within the VLAN. If the address is in the table,
then it is checked to see if it has been defined as a filter. If the MAC address is not defined as a filter,
forwarding is performed as a normal parced address.
If the specific destination MAC address is defined as a filter, the packet is forwarded to the set of
destination ports defined in the filter.
Static entries are never aged and can only be removed by user command.
✏ NOTE
Even though the above discussion pertains to the forwarding database, MAC filters are not
configured and displayed as part of the forwarding database; they are configured and
displayed separately.
Generic Attribute Registration Protocol (GARP)
This protocol is used to exchange information between GARP participants to register and de-register
attribute values within a bridged LAN. When a GARP participant declares or withdraws a given
attribute, the attribute value is recorded with the applicant state machine for that attribute for the port
from which the declaration or withdrawal was made. Registration occurs only on ports that receive
the GARP PDU containing a declaration or withdrawal. De-registration occurs only if all GARP
participants connected to the same LAN segment as the port withdraw the declaration.
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.