r0 = socket$inet6_udp(0xa, 0x2, 0x0) ioctl$sock_inet6_SIOCDELRT(r0, 0x890c, &(0x7f00000004c0)={@rand_addr=' \x01\x00', @mcast2, @ipv4={'\x00', '\xff\xff', @local}, 0x0, 0xfffd, 0x0, 0x0, 0x0, 0x1100000})