Activity $1$

Within the playground environment, run the provided server in example.com, run the provided client on h$1,$ and capture information with netstat on both the client and server.

Diagram showing activity one tasks on playground topology.

While the client$\_$ps$1.$py on host h$1$ is communicating with server$\_$ps$1.$py on host example.com, execute netstat with appropriate options on both the client and server, and copy and paste the terminal output in the designated fields below. This will require at least two runs of the client, and enough requests to provide time to issue the netstat command in another terminal window.

The client$-$server application is present within the course VM$,$ in the $/$opt$/$csc$2330/$ps$1$ directory, and should be copied to the h$1$ and example.com hosts within the playground and run there. It is derived from the example in Chapter $7,$ A Simple Protocol. Its behavior is not the same as the textbook example.

The client still submits part of an aphorism from the Zen of Python, and the server responds with the remainder of it$.$ The client randomly selects aphorisms to request from a pool of four. We will run the experiment to capture the conversation between the client and server and examine its contents.

Running the experiment

The server is located within the course VM$,$ at the path $/$opt$/$csc$2330/$ps$1/$server$\_$ps$1.$py$,$ and should be copied to the example.com host to be run.

The example.com host must be accessed via SSH to execute commands and run programs on it$.$

The server is started with the following options $($this listing reproducible with the $-$h option$)$:

usage: server$\_$ps$1.$py $[-$h$][-$p port$]$ host

simple single$-$threaded server

positional arguments:

host IP or hostname

optional arguments:

$-$h$,--$help show this help message and exit

$-$p port TCP port

When starting server$\_$ps$1.$py on host example.com, use the last $5$ digits of your student ID as the port number on the server. e$.$g$.,$ The last $5$ digits of u$0000234$ are $00234.$

If the first one or more digits $($from the last $5$ digits of your student ID$)$ are zeros,

replace them with $1$s$.$ e$.$g$.,00234$ becomes $11234.$

If the server doesn't run because the port number is occupied,

increment the number by $1.$ e$.$g$.,$ If $11234$ is occupied then use $11235.$

So$,$ if our student ID dictated that we use port $11234,$ then we will start the server by:

python$3./$server$\_$ps$1.$py example.com $-$p $11234$

The server will output messages to the terminal when a client connects and disconnects, and continue to run until stopped with Ctrl$+$C$.$

The client is located within the course VM$,$ at the path $/$opt$/$csc$2330/$ps$1/$client$\_$ps$1.$py and should be copied to the h$1$ host to be run.

The h$1$ host must be accessed via SSH to execute commands and run programs on it$.$

The client is run with the following options $($this listing is reproducible with the $-$h option$)$:

usage: client$\_$ps$1.$py $[-$h$][-$e$][-$p port$]-$s student$\_$id $-$c count host

positional arguments:

host IP or hostname

optional arguments:

$-$h$,--$help show this help message and exit

$-$e cause an error

$-$p port TCP port $($default $1060)$

$-$s student$\_$id Your student ID e$.$g$.$ u$1234567$

$-$c count How many times to request an aphorism

The conversation between client and server must take enough time for you to run netstat in another terminal window.

To make the conversation last longer, specify more aphorism requests with the $-$c option.

Specify that netstat should show active TCP connections, UDP connections, numerical addresses and programs.

$1\mathrm{.}1$: Provide your terminal output from the netstat command on example.com.

$1\mathrm{.}2$: Provide your terminal output from the netstat command on h$1.$

$1\mathrm{.}3\mathrm{.}1$: What was the process ID of server$\_$ps$1.$py when running on example.com?

$1\mathrm{.}3\mathrm{.}2$: What was the process ID of the client$\_$ps$1.$py when it ran on h$1?$

$1\mathrm{.}3\mathrm{.}3$: Which port number was server$\_$ps$1.$py using to send packets to h$1?$

$1\mathrm{.}3\mathrm{.}4$: Which port number, on h$1,$ did server$\_$ps$1.$py last send a packet to$?$

$1\mathrm{.}3\mathrm{.}5$: Which port number did client$\_$ps$1.$py last use to send packets to example.com?

$1\mathrm{.}3\mathrm{.}6$: What was the public IP address that was used by server$\_$ps$1.$py$?$

$1\mathrm{.}3\mathrm{.}7$: What was the public IP address that server$\_$ps$1.$py used to communicate with client$\_$ps$1.$py$?$

$1\mathrm{.}3\mathrm{.}8$: What is the private IP address of h$1?$