IGMP Snooping timers

Timer and counter relationships
The above timers and counters are related to each other and to others in RFC 2236 by the following formula:

  • Last Member Query Count = Robustness Variable
  • Default Timeout Interval = (Robustness Variable * Default Query Interval) + one Query Response Interval in seconds
  • Startup Query Count = Robustness Variable
  • The Startup Query Count is the number of General Queries that the Querier sends when it starts up.
  • Other Querier Timeout = (Robustness Variable * Default Query Interval) + (Query Response Interval in seconds/2)
  • The Other Querier Timeout is the length of time that a potential Querier waits after receiving a Query before it assumes that it should become the Querier.

IGMP Snooping i IGMP Snooping Proxy (DCN S5750E-16X)

Przełącznik domyślnie działa w trybie IGMP Snooping Proxy, dlatego należy wskaząc mu adres IP źródła queriera.

ip igmp snooping
ip igmp snooping vlan 222
ip igmp snooping vlan 222 l2-general-querier-version 2
ip igmp snooping vlan 222 l2-general-querier-source

Wyłączenie trybu IGMP Snooping Proxy.

ip igmp snooping
no ip igmp snooping proxy
ip igmp snooping vlan 222

Ustawienia opcjonalne dla obu przypadków.

ip igmp snooping vlan 222 mrouter-port interface Ethernet1/0/1 # statyczne wskazanie źródła multicastów 
ip igmp snooping vlan 222 report suppression # ograniczna do jednego ilość wysyłanych zapytań o konkretną grupę multicastową