Testing Phase1 Router

FILES: the following files should present in the working directory

- test1.pl
  the testing script

- Makefile and source code 

- topoXX
  the topology file assigned to you. XX is the topology number. 

- rtable
  the regular routing table file

- rtable2
  a modified routing table file, with an invalid gateway to the application
  server. 
  
  E.g., if the regular rtable is  
  
    172.24.74.213 172.24.74.213 255.255.255.255  eth1
    172.24.74.228 172.24.74.228 255.255.255.255  eth2
    0.0.0.0 172.24.74.17 0.0.0.0  eth0

  Change the gateway to an address that does not exist in your topology, say 172.24.74.100:

    172.24.74.213 172.24.74.100 255.255.255.255  eth1
    172.24.74.228 172.24.74.100 255.255.255.255  eth2
    0.0.0.0 172.24.74.17 0.0.0.0  eth0

*** Your router will be tested on a different topology. Make sure you don't hard
*** code anything about your topology in the source code.

RUN TESTS:

1. re-compile binary:

    make clean;
    make;

Don't submit the binary. I'll recompile it using your source code and Makefile.

2. start the router:

    ./sr -t XX -s vns-1.stanford.edu -r rtable;

3. in another terminal, test ping, traceroute and web. (ftp will not be tested.)

    ./test1.pl topoXX ping all;
    
    ./test1.pl topoXX tr all;

    ./test1.pl topoXX web all;

The above tests the most important functionality, (1)-(4) listed in 
http://www.cs.arizona.edu/classes/cs525/fall07/project/assignments/sr.html. 
A working router should be able to breeze through these simple tests.

In most cases the ping test should return 100%. If your router has persistent
packet loss (< 100%), there's something wrong with the router.

4. stop the router.

5. start the router with logging turned on and use the modified routing table.

    ./sr -t XX -s vns-1.stanford.edu -r rtable2 -l logfile;

6. in another terminal, 

    ./test1.pl topoXX unreach;

This will ping application server 30 times, and then send a TCP packet to the
router itself.

7. stop the router.

8. examine the log file:

    tcpdump -r logfile;

I'm looking for correct behavior according to the required functionality (5)-(8)
listed in http://www.cs.arizona.edu/classes/cs525/fall07/project/assignments/sr.html: 
since the gateway to application server is invalid, your router should send 5 ARP requests
before timing it out and sends back a Host Unreachable message; not losing
packets while waiting for the ARP reply; caching the ethernet address of the
default router (to internet) for 15s; responding with a Port Unreachable message
to the TCP packet.