Tom:
Are we assuming in the homework that the two computers (source anmd destination) are on the same ethernet network? Does this even matter, or are we headed in the wrong direction? -Matt

It definitely matters (so I guess you are headed in the right direction). You can not assume that the two machines are on the same ethernet. They may be on two distinct ethernets that are only interconnected because they are part of a larger internet (or they may be on the same ethernet).

Tom

Tom,
We're having trouble understanding IP. Will the router of the source machine know how to get the message to the router of the destination machine if the IP address given is that of the exact destination machine and not the destination router? (assuming different ethernets with different routers)

-Grant & Matt

The IP address in a packet must always be the address of the final destination. Each router has enough information to figure out what the next router is on the "best" path to the destination network.

Tom