ARP: resolve IP multicast

[sergachev]

According to RFC1112, addresses 224.0.0.0 – 239.255.255.255 (starting 0b1110) should be resolved by placing the low-order 23-bits of the IP address into the low-23 bits of the Ethernet multicast address 01-00-5E-00-00-00. Another explanation here.
This allows, for instance, sending multicast PTP packets to 224.0.1.129, which maps to 01:00:5e:00:01:81.

[gncemre23]

According to RFC1112, addresses 224.0.0.0 – 239.255.255.255 (starting 0b1110) should be resolved by placing the low-order 23-bits of the IP address into the low-23 bits of the Ethernet multicast address 01-00-5E-00-00-00. Another explanation here. This allows, for instance, sending multicast PTP packets to 224.0.1.129, which maps to 01:00:5e:00:01:81.

Do we need to implement IGMP protocol to receive the multicast IP packets?

[sergachev]

Do we need to implement IGMP protocol to receive the multicast IP packets?

If your switch / router does IGMP snooping - yes, your device needs to send an IGMP join message to start receiving multicast.

[gncemre23]

Do we need to implement IGMP protocol to receive the multicast IP packets?

If your switch / router does IGMP snooping - yes, your device needs to send an IGMP join message to start receiving multicast.

Thank you, that saves my life :)