Inconformity between RFC and implementation about ethernet IPv6 multicast address -


in rfc2464, prefix of ethernet ipv6 multicast address defined 33:33, captured packets in wireshark, found prefix implemented 33:33:ff.

for example, when sending icmpv6 neighbour solicitation packet, destination mac address captured 33:33:ff:f8:67:0d, , last bits of destination ip address ...:d3f5:31f8:670d. rfc2464, mac address should 33:33:31:f8:67:0d.

so rfc deprecated? how should implement in program?

you looking @ solicited node multicast address. trying convert directly ipv6 unicast address of node ethernet mac address, missing step in between. multicast mac address first convert node's unicast ipv6 address solicited node multicast ipv6 address described in section 2.7.1 of rfc2373. multicast mac address corresponds ipv6 multicast address described in section 7 of rfc2464.

an example: let's start ipv6 address 2001:db8::d3f5:31f8:670d. corresponding solicited node ipv6 multicast address ff02:0:0:0:0:1:fff8:670d. apply algorithm multicast mac address of 33:33:ff:f8:67:0d.

in applications shouldn't need worry neighbour discovery though. operating system's job. when using multicast in application should bind/subscribe ipv6 multicast address , operating system deliver packets destined multicast address application. if doing multicast on different lans involve other protocols mldv2 (multicast listener discovery version 2) between host , multicast router , multicast routing protocols pim-sm (protocol independent multicast - sparse mode) between multicast routers.


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