D-Link DGS-3426 User Manual - Page 152

xStack DGS-3400 Series Layer 2 Gigabit Ethernet Managed Switch The following parameters may be viewed or modified: Parameter Description 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. Query Interval The Query Interval field is used to set the time (in seconds) between transmitting IGMP queries. Entries between 1 and 65535 seconds are allowed. Default = 125. Max Response Time This determines the maximum amount of time in seconds allowed before sending an IGMP response report. The Max Response Time field allows an entry between 1 and 25 (seconds). Default = 10. Robustness Variable Adjust this variable according to expected packet loss. If packet loss on the VLAN is expected to be high, the Robustness Variable should be increased to accommodate increased packet loss. This entry field allows an entry of 1 to 255. Default = 2. Last Member Query Interval This field specifies the maximum amount of time between group-specific query messages, including those sent in response to leave group messages. Default = 1. 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. Route 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. 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. Querier State Choose Enabled to enable transmitting IGMP Query packets or Disabled to disable. The default is Disabled. State Select Enabled to implement IGMP Snooping. This field is Disabled by default. Fast Leave The Fast Leave option may be enabled or disabled (default). This allows an interface to be pruned without sending group-specific queries. Click Apply to implement the new settings. Click the Show All IGMP Snooping Entries link to return to the IGMP Snooping Settings window. Router Port Settings A static router port is a port that has a multicast router attached to it. Generally, this router would have a connection to a WAN or to the Internet. Establishing a router port will allow multicast packets coming from the router to be propagated through the network, as well as allowing multicast messages (IGMP) coming from the network to be propagated to the router. A router port has the following behavior: • All IGMP Report packets will be forwarded to the router port. • IGMP queries (from the router port) will be flooded to all ports. All UDP multicast packets will be forwarded to the router port. Because routers do not send IGMP reports or implement IGMP snooping, a multicast router connected to the router port of a Layer 3 switch would not be able to receive UDP data streams unless the UDP multicast packets were all forwarded to the router port. A router port will be dynamically configured when IGMP query packets, RIPv2 multicast, DVMRP multicast or PIM-DM multicast packets are detected flowing into a port. To view this window click L2 Features > IGMP Snooping > Router Port Settings. 138