Embed Size (px)
Citation preview
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Chapter 21
Trivial FileTransfer Protocol
(TFTP)
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
CONTENTSCONTENTS• MESSAGES• CONNECTION• DATA TRANSFER• UDP PORTS• TFTP EXAMPLE• TFTP OPTIONS• SECURITY• APPLICATIONS
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
TFTP uses the services of UDP TFTP uses the services of UDP on the well-known port 69.on the well-known port 69.
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
MESSAGES
21.121.1
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-1
Message categories
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-2
RRQRead request
Mode: netascii or octet
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-3
WRQWrite request
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-4
DATA format
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-5
ACK format
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-6
ERROR format
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
CONNECTION
21.221.2
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-7
Connection establishment
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
DATATRANSFER
21.321.3
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-8Sorcerer’s apprentice bug
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
UDPPORTS
21.421.4
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-9
UDP port numbers used by TFTP
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
21.521.5
TFTPEXAMPLE
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-10
TFTPexample
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
TFTPOPTIONS
21.621.6
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
SECURITY
21.721.7
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-11
TELNET with FTP for security
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
21.821.8
APPLICATIONS
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000
Figure 21-12
Use of TFTP with BOOTP
