3com S7906E インストール手順

 

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If not statically configured, the startup query interval is 1/4 of the “IGMP query interval”. By default, 

the IGMP query interval is 60 seconds, so the startup query interval = 60 / 4 = 15 (seconds). 

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If not statically configured, the startup query count is set to the IGMP querier robustness variable. 

By default, the IGMP querier robustness variable is 2, so the startup query count is also 2.  

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If not statically configured, the other querier present interval is [ IGMP query interval ] times [ IGMP 

robustness variable ] plus [ maximum response time for IGMP general queries ] divided by two. The 

default values of these three parameters are 60 (seconds), 2 and 10 (seconds) respectively, so the 

other querier present interval = 60 × 2 + 10 / 2 = 125 (seconds).  

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If statically configured, the startup query interval, the startup query count, and the other querier 

present interval take the configured values.  

 

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Make sure that the other querier present interval is greater than the IGMP query interval; otherwise 

the IGMP querier may change frequently on the network.  

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Make sure that the IGMP query interval is greater than the maximum response time for IGMP 

general queries; otherwise, multicast group members may be wrongly removed.  

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The configurations of the maximum response time for IGMP general queries, the IGMP last 

member query interval and the IGMP other querier present interval are effective only for IGMPv2 or 

IGMPv3. 

 

IGMP fast leave processing is implemented by IGMP Snooping. For details, refer to IGMP Snooping 

Configuration in the IP Multicast Volume. 

Due to some possible restrictions, some receiver hosts on an SSM network may run IGMPv1 or 

IGMPv2. To provide SSM service support for these receiver hosts, you need to configure the IGMP 

mapping feature on the last hop router. 

Before configuring the IGMP SSM mapping feature, complete the following tasks: 

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Configure any unicast routing protocol so that all devices in the domain are interoperable at the 

network layer. 

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Configure basic functions of IGMP. 

Follow these steps to enable the IGMP SSM mapping feature: