There will be a "semester" paper/project due
     July 2003                             by July 28th or earlier.
Su Mo Tu We Th Fr Sa
       1  2  3  4  5             Assignments will be given at least two
 6  7  8  9 10 11 12                                 days ahead of time.
13 14 15 16 17 18 19      Exam #1 will be on either July 18 or July 21.
20 21 22 23 24 25 26
27 28 29 30 31            Exam #2 will be on August 1st.

     My office phone number is 273-7172 and 
the CEEE 20 classroom phone is 273-3823, where I will be most of the time.

1. TCP/IP protocol is divided into 5 layers instead of using the OSI 7 layer model. TCPIP protocol layers.

    We looked at the Network layer when we examined the ethereal captured
    IP header.  This was right after the ethernet header.
   
    What did the ethernet header have?
   
    Destination address  6 bytes or 48 bits, for the NIC (Network Interface Card)
                         Where the packet is to be delivered.  The address
                         is a physical address.
    Source address       This would be the 6 bytes MAC or NIC address of the 
                         sender.  
                         The return address you put on your U.S. Postal mail
                         is the source.
    Type                 Either ARP or IP is the type.
   
    What did the IP header have?  IP addresses, which are 4 bytes or 32 bits.
    IP addresses allow internetworking.  The internet is a network of networks.
   
    The IP address of the UNI web server at www.uni.edu is: 134.161.1.13
                                           panther.uni.edu [134.161.1.13]
   
    The IP address of iceman.uni.edu is:   134.161.1.41
                                           iceman.uni.edu [134.161.1.41]
   
    The IP addresses above are shown in dotted decimal format w.x.y.z
    and each decimal number represents an 8 bit value.
   
    IP addresses are only 32 bits, whereas NIC or NAC or MAC addresses are 48.
   
    NIC - Network Interface Card      NAC - Network Adaptor Card
    MAC - Media Access Control or Card
   
    ARP stands for Address Resolution Protocol
   
    ARP REQUEST
    Who has IP address a.b.c.d?  Please tell host with IP address r.s.t.u!
   
    ARP REPLY
    I have IP address a.b.c.d and my NIC address is F8:11:AC:35:44:3D
                      -------                       -----------------
    
    What did those TCP headers have?
   
    Port numbers like port 23 for telnet, for example.  Or port 80 for HTTP.
    Or port 25 for SMTP.
    
    The IP or networking level layer gets the packet from one machine to
    another machine across the internet, on different networks, if necessary.
   
    The TCP port numbers help deliver the information to or from the 
    correct application.  You might be running several copies of the
    web browser, plus using telnet, plus using ssh, plus using ftp.
    The port number is how the incoming information gets TRANSPORTed
    to the right application that needed it.                  ----
   

2. Packets are shown using hexadecimal digits: Binary, hexadecimal (base 16), octal (base 8) and the using the bc calculator program.

3. What commands do I need to utilize in order to use the snort or the ethereal or the tcpdump sniffer software in the CEEE lab?

       xhost +
       sudo ethereal
   

4. Sending email using the SMTP protocol, without utilizing a user agent like pine or elm or eudora or MailMan or MailSpinner. SMTP and port 25. Illustrates the issue of authentication.

5. Using the ethereal program.

6. Encrypting strings using the PERL crypt function. This function is often used to encrypt passwords.

   > perl -e '$text=crypt "Hello", "AC"; print $text . "\n\n";'
   
     AC8pVV/TJYqaQ
   
   > perl -e '$text=crypt "HellO", "AC"; print $text . "\n\n";'
   
     ACst99XYal30s
   
   > perl -e '$text=crypt "HellO", "DC"; print $text . "\n\n";'
   
     DCWdiweUBDywo