Can I use broadcast or multicast for TCP?

Question

For Internet Protocol (IP) I can use multicast:

• in IPv4: Internet Group Management Protocol (IGMP)
• in IPv6: Multicast Listener Discov

Answer 1

No, you can't. TCP is a protocol for communication between exactly two endpoints. Compared to UDP it features reliable transport, that means, that packets get not only send, but it is expected that the peer acknowledges the receipt of the data and that data will be retransmitted if the acknowledgement is missing. And because Broadcast and Multicast only send but never receive data, the reliability of TCP cannot be implemented on top of these protocols.