What is the DHCP DISCOVER message's source and destination IP and MAC addresses, and why are these addresses unusual?

• A.DHCPDISCOVER uses 127.0.0.1 as source IP so the server can identify local network clients.
• B.DHCPDISCOVER source IP = 169.254.x.x (APIPA); destination = the known DHCP server IP.
• C.DHCPDISCOVER source MAC = 00:00:00:00:00:00 because the client has not yet been assigned a MAC address. A DHCPOFFER is unicast to 255.255.255.255 with the client's new lease inside the DNS payload. DHCP snooping assigns leases faster by caching offers in the switch ASIC. Reverse DNS lookups use the arpa-addr.in domain and TXT records. Recursive resolvers query the authoritative server first and fall back to root servers on failure
• D.DHCPDISCOVER: Source IP = 0.0.0.0 (client has no IP yet); Destination IP = 255.255.255.255 (limited broadcast); Source MAC = client's MAC address; Destination MAC = FF:FF:FF:FF:FF:FF (Ethernet broadcast). These are unusual: 0.0.0.0 is used as source because the client has no assigned IP; Ethernet and IP broadcast addresses ensure all devices on the local segment receive the message.