N$8\mathrm{.}5.$ When we use VPN to reach Facebook, which is blocked by our firewall, we route our

Facebook$-$bound packets towards the TUN interface to reach the VPN server via the

tunnel. The VPN server will route our packets towards Facebook $($via the Internet$).$

When Facebook sends reply to us$,$ will the packet be sent directly to us $($i$.$e$.,$ without

going through the tunnel$),$ or to the VPN server $($and then go through the tunnel$)?$

Please explain why.

N$8\mathrm{.}6.$ A website in California only allows machines in California to access it$.$ The way how

it enforces the rule is to check whether a visitor's IP address is from California or not.

You live in Carbondale, IL$,$ and you desperately want to visit this website. Please

describe how you can do it$.$

N$8\mathrm{.}7.$ The following code snippet creates a TUN interface. What are the possible names of

this interface?

tun $=os.$open$(\frac{?}{de}\frac{v}{n}e\frac{t}{t}un,os.O_{R}DWR)$

ifr $=$ struct.pack$(\text{'}16sH\text{'},$ b'ab$\frac{c}{\%}d\text{'},IF{F}_{T}UN|IF{F}_N{O}_{P}I)$

$ifnam{e}_b$ytes $=fcntl.$ioctl$(tun,$ TUNSETIFF, ifr$)$

N$8\mathrm{.}9.$ When we read data from the TUN interface, which of the following is most likely the

first byte of the data: $($A$)012,($B$)023,($C$)034,($D$)045,($E$)056?$

N$8\mathrm{.}10.$ The $"$ip route" command shows the following results.

What will be the source IP of each packet if we send the packet to the following ad$-$

dresses, respectively.

$1\mathrm{.}1\mathrm{.}1\mathrm{.}1$

$10\mathrm{.}0\mathrm{.}5\mathrm{.}9$

$192\mathrm{.}168\mathrm{.}53\mathrm{.}7$

$10\mathrm{.}0\mathrm{.}6\mathrm{.}6$

N$8\mathrm{.}11.$ On the VPN server, why do we need to turn on the IP forwarding?

N$8\mathrm{.}12.$ After setting up the VPN$,$ we run tcpdump to monitor the traffic on all the

interfaces $($lo$,$ tun $0,$ and eth$0).$ We see the following packets. Please describe

which interface each of the packets come from.