R1. Describe the two parts of an IP address.
R2. Provide a step-by-step description of how a packet is routed, assuming that it must traverse at least one router.
R3. Why are there two separate, standard internet transport protocols: TCP and UDP? How are they similar? How are they different?
R4. Why do some web sites block "ping" requests? Explain whether or not web sites still need to do this.