718 Configuring L2 Multicast FeaturesWhat Are GARP and GMRP?Generic Attribute Registration Protocol (GARP) is a general-purpose protocolthat registers any network connectivity or membership-style information.GARP defines a set of switches interested in a given network attribute, suchas VLAN ID or multicast address.PowerConnect M6220, M6348, M8024, and M8024-k switches can use GARPfunctionality for two applications:• GARP VLAN Registration Protocol (GVRP) to help dynamically manageVLAN memberships on trunk ports• GARP Multicast Registration Protocol (GMRP) to help control theflooding of multicast traffic by keeping track of group membershipinformation.GVRP and GMRP use the same set of GARP Timers to specify the amount oftime to wait before transmitting various GARP messages.GMRP is similar to IGMP snooping in its purpose, but IGMP snooping ismore widely used. GMRP must be running on both the host and the switch tofunction properly.Default L2 Multicast ValuesAll L2 multicast features are disabled by default. Details about the L2multicast are in Table 25-1.Table 25-1. L2 Multicast DefaultsParameter Default ValueBridge Multicast Filtering DisabledIGMP Snooping mode DisabledMLD Snooping mode DisabledBridge multicast group None configuredBridge multicast forwarding mode Forward unregisteredIGMP/MLD snooping Disabled on all interfacesIGMP/MLD snooping auto-learn DisabledIGMP/MLD snooping host timeout 260 seconds
