D-Link DGS-3212SR, Руководство пользователя, Страница: 67 / 140

D-Link DGS-3212SR Layer 2 Gigabit Ethernet Switch
Parameter Description
Query Interval
The Query Interval field is used to set the time (in seconds) between
transmitting IGMP queries. Entries between 1 and 9,999 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 2 to 255. Default = 2.
Last Member Query
Interval
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.
Querier State
Choose Querier to enable transmitting IGMP Query packets or Non-
Querier to disable. The default value is Non-Querier .
State
Select Enabled to implement IGMP Snooping. This is Disabled by
default.
Static Router Ports
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 the Layer 3
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