Assume two stations, A and B, are connected by two intermediate routers.
Now, when A sends a packet to B, then the OSI model will come into the picture. Like, A's TCP layer will add A's port address (let's say x), and then the Network layer will set the Source IP address as A and Destination IP address as B. I understand till this point, but I have some confusion regarding the next process. I am listing the it below:
- What will be the destination MAC address in the DLL header when A is transmitting? Will it be R1's address or B's address?
- If A has sent a packet to R1, will R1 change network header here, or will it only read the destination IP address and forward to R2 as is without any modification?
- At R1, the only sublayers of OSI that will be accessed are Physical layer, DLL, and Network layer only? Is this correct understanding?
- Will R1 change the destination MAC address in the DLL, and set it to R2's address, or will it be B's MAC address in DLL throughout the communication?
I don't feel the need to separate this into four questions. Please let me know if this is not allowed here.