To solve this problems, administratively scoped IPv4 multicast regions were established in 1994. (see D. Meyer's "Administratively Scoped IP Multicast" Internet draft). It does scoping based on multicast addresses rather than on TTLs. The range 239.0.0.0 to 239.255.255.255 is reserved for this administrative scoping. Loopback.
Azure ad connect url whitelist