3Com 3C16476A - Baseline Switch 2250, Руководство пользователя

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42 C
HAPTER
4: C
ONFIGURING THE
S
WITCH
After all the bridges on the network have determined
the configuration of their ports, each bridge only
forwards traffic between the Root Port and the ports
that are the Designated Bridge Ports for each network
segment. All other ports are blocked, which means
that they are prevented from forwarding traffic.
To use spanning tree, choose enabled from the drop
State down menu, fill in the setup parameters, and
click
Apply .
Figure 34 Spanning Tree Screen
IGMP Snooping
This switch uses IGMP (Internet Group Management
Protocol) to query for any attached hosts that want to
receive a specific multicast service. It identifies the
ports containing hosts requesting to join the service
and sends data out to those ports only. It then
propagates the service request up to any neighboring
multicast switch/router to ensure that it will continue
to receive the multicast service. This procedure is
called multicast filtering.
The purpose of IP multicast filtering is to optimize a
switched network’s performance, so multicast packets
will only be forwarded to those ports containing
multicast group hosts or multicast routers/switches,
instead of flooding traffic to all ports in the subnet
(VLAN).
Choose enable or disable from the IGMP Snooping
Mode drop down menu.
Figure 35 IGMP Snooping Setup Screen
IGMP Query
Choose enable or disable from the IGMP Query Mode
drop down menu.
Figure 36 IGMP Query Setup Screen