GARP (Generic Attribute Registration Protocol) defines the architecture, rules of operation, state machines and variables for the registration and de-registration of attribute values. It allows dynamic filter entries for VLAN membership to be distributed among the Forwarding Databases of VLAN-aware switches. By joining GVRP (GARP VLAN Registration Protocol), it helps maintaining VLAN information. The rule of the aging scheme is:
GARP Leave All Time > GARP Leave Time > GARP Join Time
NOTE:: Before GVRP can be enabled, STP must be enabled, saved, and switch must go through a Cold Start in order for configuration to take effect.
IGMP Configuration
Figure 4-27. IGMP Configuration Menu
Multicasting is used to support real-time applications such as video conferencing or streaming audio. IGMP (Internet Group Multicast Protocol) allows you to query for any attached hosts who want to receive a specific multicast service. The switch looks up the IP Multicast Group used for this service and adds any port, which received a similar request to that group. It then propagates the service request on to any neighboring multicast switch to ensure that it will continue to receive the multicast service.
By supporting IGMP (Internet Group Management Protocol) Snooping, the switch can forward multicast traffic intelligently. Packets are forwarded to the ports that belong to the multicast group instead of being broadcasted to all ports and possibly