Phase 1

Here’s the info we found from Gene Block’s notepad:

DISCOVERY!!

[email protected] block

clk 1996

From this, we can deduce that we need to connect to [email protected] with password block. The next step is to connect to host clk and port 1996.

# Get the IP address of clk
$ dig clk

# Solve phase
$ ./socket
> socket
> connect 3 10.0.124.247 1996
> send 3 GET /
> recv 3 2000
> close 3
> ^D

We get our response:

HTTP/1.0 200 OK
Content-Type: text/plain

Let's keep this simple. 
There's nothing to see here! I promise. 
It's true that immortality allows for ***persistence***. 
I wrote that down on page 17 of my Tuesday's class notes. Hopefully I won't 
forget them again.
I should start uploading them on my servers. Maybe I'll have less of a request
for comments.

Hint: Check BruinLearn! The next host should be 3 characters and the port is 4 
digits. Remember, be persistent.

Phase 2

From the response, we know to check BruinLearn and Tuesday's lecture slides on HTTP. Check page 17. Regarding persistence, we see that our target is RFC2616—so, our host is rfc and port is 2616.

$ dig rfc

$ ./socket
> socket
> connect 3 10.0.78.200 2616
> send 3 GET /
> recv 3 2000
> ^D

We get our response:

HTTP/1.0 404 Not Found
Content-Type: text/plain

You got lucky last time...you're gonna have to guess where I'm hiding this 
time. Here's a nice problem for you:

Imagine I wanted to send my lab notes to my wife Mrs. Block at my house. 
Between my lab computer and my house, there's one router. Hence, there are two
links. Don't ask how I know this, but the first link from my lab to the router
has a:
- propagation delay of 20 ms
- transmission rate of 5 Mbps

The second link from the router to my house has a:
- propagation delay of 5 ms
- transmission rate of 2 Mbps

My notes are 1.5 MB and packets are 500 KB each. 

How long will it take for my notes to arrive at home? You'll be able to find
the next step to immortality in milliseconds...

Hint: If the answer is 2467 ms, send GET /2467

Unfortunately, this is not as easy as phase 1—we have a problem to solve.

Solving the Problem

Here’s an image of our problem:

graph LR;
	lc[Lab Computer]
	
	lc<--5 Mbps; 20 ms-->Router
	Router<--2 Mbps; 5 ms-->Home

We know: