Mary is sending an instant message to Robert. The message will be broken into a series of packets that will traverse all network devices. What addresses will populate these packets as they are forwarded from Router1 to Router2?
The Source and Destination IP address is not going to change. Host 1 IP address will stay as being the source IP and the Host 2 IP address will stay the destination IP address. Those two are not going to change. For the MAC address it is going to change each time it goes from one hope to another. (Except switches… they don’t change anything) Frame leaving HOST 1 is going to have a source MAC of Host 1 and a destination MAC of Router1. Router 1 is going to strip that info off and then will make the source MAC address of Router1’s exiting interface, and making Router2’s interface as the destination MAC address. Then the same will happen… Router2 is going to change the source/destination info to the source MAC being the Router2 interface that it is going out, and the destination will be Host2’s MAC address.