D-Link DGS-3200-16 User Manual - Page 84

xStack® DGS-3200 Series Layer 2 Gigabit Ethernet Managed Switch The following parameters may be viewed or modified: Parameter Description VID (VLAN ID) This is the VLAN ID that, along with the VLAN Name, identifies the VLAN the user wishes to modify the IGMP Snooping Settings for. VLAN Name This is the VLAN Name that, along with the VLAN ID, identifies the VLAN the user wishes to modify the IGMP Snooping Settings for. Leave Timer This specifies the maximum amount of time in seconds between the Switch receiving a leave group message from a host, and the Switch issuing a group membership query. If no response to the membership query is received before the Leave Timer expires, the (multicast) forwarding entry for that host is deleted. The default setting is 2 seconds. Host Timeout This is the maximum amount of time in seconds allowed for a host to continue membership in a multicast group without the Switch receiving a host membership report. Default = 260. Router Timeout This is the maximum amount of time in seconds a route is kept in the forwarding table without receiving a membership report. Default = 260. State Select Enabled to implement IGMP Snooping. This field is Disabled by default. Click Apply to implement the new settings. Data Driven Learning Settings The Switch allows you to implement data driven learning for IGMP snooping groups. If data-driven learning, also known as dynamic IP multicast learning, is enabled for a VLAN, when the Switch receives IP multicast traffic on the VLAN, an IGMP snooping group is created. Learning of an entry is not activated by IGMP membership registration, but activated by the traffic. For an ordinary IGMP snooping entry, the IGMP protocol will take care of the aging out of the entry. For a data-driven entry, the entry can be specified not to age out or to age out by a timer. When the data driven learning State is enabled, the multicast filtering mode for all ports is ignored. This means multicast packets will be flooded. Please note that if a data-driven group is created and IGMP member ports are learned later, the entry will become an ordinary IGMP snooping entry. In other words, the aging out mechanism will follow the conditions of an ordinary IGMP snooping entry. Data driven learning is useful on a network which has video cameras connected to a Layer 2 switch that is recording and sending IP multicast data. The switch needs to forward IP data to a data center without dropping or flooding any packets. Since video cameras do not have the capability to run IGMP protocols, the IP multicast data will be dropped with the original IGMP snooping function. To view the following window, click L2 Features > IGMP Snooping > Data Driven Learning Settings: Figure 3 - 21. Date Driven Learning Settings window The following parameters may be viewed or modified: 71