1 © 2004, Cisco Systems, Inc. All rights reserved. CCNA 2 v3.1 Module 10 Intermediate TCP/IP

222 © 2004, Cisco Systems, Inc. All rights reserved. Objectives

333 © 2004, Cisco Systems, Inc. All rights reserved. TCP Operation The transport layer is responsible for the reliable transport of and regulation of data flow from source to destination.

444 © 2004, Cisco Systems, Inc. All rights reserved. Synchronization or Three-Way Handshake

555 © 2004, Cisco Systems, Inc. All rights reserved. Denial-of-Service Attacks

666 © 2004, Cisco Systems, Inc. All rights reserved. Simple Windowing

777 © 2004, Cisco Systems, Inc. All rights reserved. TCP Sequence and Acknowledgment Numbers

888 © 2004, Cisco Systems, Inc. All rights reserved. Positive ACK Acknowledgement is a common step in the synchronization process which includes sliding windows and data sequencing.

999 © 2004, Cisco Systems, Inc. All rights reserved. Protocol Graph: TCP/IP

10 © 2004, Cisco Systems, Inc. All rights reserved. UDP Segment Format

11 © 2004, Cisco Systems, Inc. All rights reserved. Port Numbers

12 © 2004, Cisco Systems, Inc. All rights reserved. Telnet Port Numbers

13 © 2004, Cisco Systems, Inc. All rights reserved. Reserved TCP and UDP Port Numbers

14 © 2004, Cisco Systems, Inc. All rights reserved. Ports for Clients Whenever a client connects to a service on a server, a source and destination port must be specified. TCP and UDP segments contain fields for source and destination ports.

15 © 2004, Cisco Systems, Inc. All rights reserved. Port Numbering and Well-Known Port Numbers Port numbers are divided into three different categories: well-known ports registered ports dynamic or private ports

16 © 2004, Cisco Systems, Inc. All rights reserved. Port Numbers and Socket

17 © 2004, Cisco Systems, Inc. All rights reserved. Comparison of MAC addresses, IP addresses, and port numbers A good analogy can be made with a normal letter. The name on the envelope would be equivalent to a port number, the street address is the MAC, and the city and state is the IP address.

18 © 2004, Cisco Systems, Inc. All rights reserved. Summary