Analysis of information sources in references of the Wikipedia article "Multicast address" in English language version.
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most Layer 2 switches flood all multicast traffic that falls within the MAC address range of 0x0100.5E00.00xx [...] to all ports on the switch even if IGMP Snooping is enabled. [...] There are several multicast group ranges besides the 224.0.0.0/24 that will map to the 0x0100.5E00.00xx MAC address range and hence also will be flooded by most Layer 2 switches.
In network prefix or Classless Inter-Domain Routing ( CIDR) notation, IP multicast addresses are summarized as 224.0.0.0/4.