Examine the contents of the PDU Information Window. Click the colored box in the las column for the first even. In the Simulation Panel Event List section, the last column contians a colored box that provides access to detailed information about the event. A dialog box appears indicating there are no more events to be captured.
CHAPTER 4 ACL PACKET TRACER ACTIVITY PC
The server sends the web page in two segments, and the PC acknowledges the web page. These events represent the client PC's request for DNS service, followed by the request for a web page. The exchange between the PC and the server is animated and the events are added to the Event List. Type into the URL box and click the Go button. Click on the PC in the logical workplace.
We want to capture only DNS and HTTP events. Click the Simulation tab to enter simulation mode. Sequence numbers provide reliability by identifying missing segments and allowing the reassembly of the application data by putting the segment back together in the proper order. In addition to port numbers, the TCP segment also contains sequence numbers. Segments contain port numbers that identify the service the client is requesting from the server and port numbers generated by the client to which the server should reply.
The PDU's for UDP and TCP differ substantially, but they share the notion of port numbers. UDP and TCP are TCP/IP Protocols that correspond to OSI Layer r, the Transport layer.