r0 = socket$inet6_udp(0xa, 0x2, 0x0)
r1 = dup(r0)
connect$inet6(r1, &(0x7f0000000200)={0xa, 0x4e20, 0x0, @ipv4={'\x00', '\xff\xff', @loopback}}, 0x1c)
sendmmsg$inet6(r1, &(0x7f00000007c0)=[{{0x0, 0x0, 0x0}}, {{&(0x7f0000000280)={0xa, 0x4e21, 0x0, @mcast1}, 0x1c, 0x0, 0x0, &(0x7f00000005c0)=[@pktinfo={{0x24, 0x29, 0x3e, {@private2}}}], 0x28}}], 0x2, 0x0)