Q27

An IP machine $Q$ has a path to another $IP\ machine\ H$ via three $IP\ routers \ R1, R2,$ and $R3$. $Q-R1-R2-R3-H$ $H$ acts as an $\text{HTTP}\ server$, and $Q$ connects to $H$ via $\text{HTTP}$ and downloads a file. Session layer encryption is used, with $\text{DES}$ as the shared key encryption protocol. Consider the following four pieces of information: $[I1]$ The $\text{URL}$ of the file downloaded by $Q$ $[I2]$ The $\text{TCP}$ port numbers at $Q$ and $H$ $[I3]$ The $\text{IP}$ addresses of $Q$ and $H$ $[I4]$ The link layer addresses of $Q$ and $H$ Which of $I1$, $I2$, $I3$, and $I4$ can an intruder learn through sniffing at $R2$ alone?