Update on HW3 Programming Assigment

• I was reading over the third lab just to get a general overview, and in the initial setup of the lab it says that you can see the sequence numbers of the packets for TCP. The instruction says to go to Edit -> Preferences -> Protocols -> IP and uncheck the “relative sequence numbers.” I have the latest version of Ethereal, and that is not one of the options found in the IP section? Will this be required to do the lab?

  Edit -> Preferences -> Protocols is expandable. Just click on the arrow just beside the Protocols text and the entire list of protocols will come out. Select IP from there.

• How should we connect to the smtp server? Are we to use the same format as the last program ./prog ?

  Connection to the server requires two things, the ip address of the host where the server is running and the port no. to which the server is listening. It is up to you how you get these. you can either pass it as command line argument like:

  ./prog ip-addr port-no

  or take user input once the program starts executing like

  ./prog

  ip-addr : xxx.xxx.xxx.xxx

  port-no : xxxx