1. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Chapter 21 Trivial File Transfer Protocol (TFTP)

2. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 CONTENTS MESSAGES CONNECTION DATA TRANSFER UDP PORTS TFTP EXAMPLE TFTP OPTIONS SECURITY APPLICATIONS

3. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 TFTP uses the services of UDP on the well-known port 69.

4. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 MESSAGES 21.1

5. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-1 Message categories

6. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-2 RRQ Read request Mode: netascii or octet

7. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-3 WRQ Write request

8. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-4 DATA format

9. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-5 ACK format

10. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-6 ERROR format

11. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 CONNECTION 21.2

12. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-7 Connection establishment

13. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 DATA TRANSFER 21.3

14. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-8 Sorcerer’s apprentice bug

15. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 UDP PORTS 21.4

16. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-9 UDP port numbers used by TFTP

17. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 21.5 TFTP EXAMPLE

18. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-10 TFTP example

19. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 TFTP OPTIONS 21.6

20. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 SECURITY 21.7

21. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-11 TELNET with FTP for security

22. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 21.8 APPLICATIONS

23. McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 21-12 Use of TFTP with BOOTP