3Com Switch 4800G 24-Port Configuration Manual page 572

572 C 42: IGMP S
HAPTER
Static Router Port
Configuration
n
C
NOOPING ONFIGURATION
(0.0.0.0, 224.1.1.1):
Attribute:
Host port(s):total 2 port.
GE1/0/3
GE1/0/4
MAC group(s):
MAC group address:0100-5e01-0101
Host port(s):total 2 port.
GE1/0/3
GE1/0/4
As shown above, GigabitEthernet 1/0/3 and GigabitEthernet 1/0/4 of Switch A
have joined multicast group 224.1.1.1.
Network requirements
As shown in Figure 173, Router A connects to a multicast source (Source)
■
through GigabitEthernet 1/0/2, and to Switch A through GigabitEthernet
1/0/1.
IGMP is to run between Router A and Switch A, and IGMP Snooping is to run
■
on Switch A, Switch B and Switch C, with Router A acting as the IGMP querier.
Suppose STP runs on the network. To avoid data loops, the forwarding path
■
from Switch A to Switch C is blocked under normal conditions, and multicast
traffic flows to the receivers, Host A and Host C, attached to Switch C only
along the path of Switch A-Switch B-Switch C.
Now it is required to configure GigabitEthernet 1/0/3 that connects Switch A to
■
Switch C as a static router port, so that multicast traffic can flows to the
receivers nearly uninterruptedly along the path of Switch A-Switch C in the
case that the path of Switch A-Switch B-Switch C gets blocked.
If no static router port is configured, when the path of Switch A-Switch B-Switch C
gets blocked, at least one IGMP query-response cycle must be completed before
the multicast data can flow to the receivers along the new path of Switch
A-Switch C, namely multicast delivery will be interrupted during this process.
Host Port
(D) ( 00:03:23 )
(D) ( 00:03:23 )