Assuming that the routing tables are up to date and no ARP messages are needed, after a packet leaves H1, how many times is the L2 header rewritten in the path to H2?
Number of times the L2 header is rewritten in the path from H1 to H2 depends on the number of Layer 2 devices in the network topology
Assuming that the routing tables are up to date and no ARP messages are needed, the Layer 2 (L2) header in the packet is typically rewritten each time it passes through a Layer 2 device, such as a switch or a bridge.
This is because each Layer 2 device usually adds or modifies the L2 header to include its own MAC address as the source address and the MAC address of the next hop as the destination address.
In the path from H1 to H2, the packet likely passes through several switches or bridges (assuming it is an Ethernet network).
Each of these Layer 2 devices will rewrite the L2 header with its own MAC addresses before forwarding the packet to the next hop.
Therefore, the L2 header is likely to be rewritten several times in the path to H2, and the exact number of times depends on the number of Layer 2 devices the packet passes through.
In summary, the number of times the L2 header is rewritten in the path from H1 to H2 depends on the number of Layer 2 devices in the network topology, as each device will typically modify the L2 header.
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