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.
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: 22.214.171.124 panther.uni.edu [126.96.36.199] The IP address of iceman.uni.edu is: 188.8.131.52 iceman.uni.edu [184.108.40.206] 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. ----
xhost + sudo ethereal
> 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