In this problem we investigate whether either UDP or TCP provides a degree of end-point authentication.
a. Consider a server that receives a request within a UDP packet and responds to that request within a UDP packet (for example, as done by a DNS server). If a client with IP address X spoofs its address with address Y, where will the server send its response?
b. Suppose a server receives a SYN with IP source address Y. and after responding with a SYNACK. receives an ACK with IP source address Y with the correct acknowledgement number. Assuming the server chooses a random initial sequence number and there is no "man-in-the-middle," can the server be certain that the client is indeed at Y (and not at some other address X that is spoofing Y)?