What will R1 do with the Ethernet frame header after PC1 sends a packet to PC2?

When PC1 sends a packet to PC2, the data encapsulation process involves several layers of the OSI model. The Ethernet frame header includes MAC address information specific to the local network segment. When the router (R1) receives the Ethernet frame, it recognizes that the frame is not destined for itself but rather intended for another device (PC2), which is on a different network.

In this scenario, R1 will strip off the Ethernet header that was originally attached to the frame by PC1 to process the packet. Subsequently, it will need to encapsulate this packet within a new Ethernet frame that is appropriate for the next hop on the way to its final destination, PC2. This means R1 must add a new Layer 2 header that contains the appropriate MAC addresses, specifically the MAC address of the next device on the route (likely a switch if PC2 is on a different segment).

This action of removing the original Ethernet header and adding a new Layer 2 header is essential in ensuring that the packet retains the necessary addressing information for successful delivery through the subsequent networks. Therefore, the correct answer highlights the requirement for R1 to manage the Layer 2 addressing as it forwards packets across different collision domains or network segments.