复件 M0 02 tcp-ip

SYN received
3
Established (seq=101 ack=301 ctl=ack)
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-13
TCP Simple Acknowledgment
Sender Receiver
Window size = 1
ICND—8-11
TCP Three Way Handshake/Open Connection
Host A Host B
1
Send SYN (seq=100 ctl=SYN) SYN received Send SYN, ACK 2 (seq=300 ack=101 ctl=syn,ack)
SYN received
ICND—8-15
TCP Simple Acknowledgment
Sender Send 1 Receive ACK 2 Receiver Receive 1 Send ACK 2
Window size = 1
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-16
www.cisco.com
ICND—8-10
TCP Three Way Handshake/Open Connection
Host A Host B
1
Send SYN (seq=100 ctl=SYN) SYN received
© 1999, Cisco Systems, Inc.
www.cisco.com
I just sent #10.
Source Dest. Seq. Ack. 1028 23 10 1
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-21
TCP Sequence and Acknowledgment Numbers
Source Port Dest. Port Sequence # Acknowledgement # …
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-14
TCP Simple Acknowledgment
Sender Send 1 Receiver Receive 1
Window size = 1
© 1999, Cisco Systems, Inc.
www.cisco.com
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-3
Introduction to TCP/IP
Host Host
Internet TCP/IP
Early protocol suite
Universal
© 1999, Cisco Systems, Inc.
Receive 3
Window size = 1
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-19
TCP Simple Acknowledgment
Sender Send 1 Receive ACK 2 Send 2 Receive ACK 3 Send 3 Receive ACK 4 Receiver Receive 1 Send ACK 2
2
2
1
Data Link
1
Physical
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-5
Application Layer Overview
File Transfer - TFTP * - FTP * - NFS E-Mail - SMTP Remote Login - Telnet * - rlogin * Network Management - SNMP * Name Management - DNS*
ICND—8-7
TCP Segment Format
Bit 0 Source port (16) Bit 15 Bit 16 Destination port (16) Bit 31
Sequence number (32) Acknowledgement number (32)
Header length (4)
• Identify the IP protocol stack, its protocol layer functions, and commonly used IP protocols
• Identify IP address classes, IP addresses, IP subnet masks, IP network numbers, subnet numbers, and possible host numbers. • Configure IP addresses and subnet masks on a router interface and optionally configure a host table. • Interconnect the VLANs with a layer three device such as a router on a stick.
Source Dest. Seq. Ack. 23 1028 1 11
1028 23 11 2
© 1999, Cisco Systems, Inc.
Source Dest. Seq. Ack.
www.cisco.com
ICND—8-23
TCP Sequence and Acknowledgment Numbers
Transmission Control Protocol (TCP)
User Datagram Protocol (UDP)
ConnectionOriented
Connectionless
Internet
Data Link
Physical
© 1999, Cisco Systems, Inc.
www.cisco.com
TCP Simple Acknowledgment
Sender Send 1 Receive ACK 2 Send 2 Receiver Receive 1 Send ACK 2
Receive 2
Window size = 1
© 1999, Cisco Systems, Inc.
www.cisco.com
I just sent #10.
I just got #10, now I need #11.
Source Dest. Seq. Ack. 1028 23 10 1
Source Dest. Seq. Ack. 23 1028 1 11
© 1999, Cisco Systems, Inc.
www.cisco.com
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-12
TCP Three Way Handshake/Open Connection
Host A Host B
1
Send SYN (seq=100 ctl=SYN) SYN received Send SYN, ACK 2 (seq=300 ack=101 ctl=syn,ack)
1028 23 11 2 Source Dest. Seq. Ack. 23 1028 2 12
www.cisco.com
ICND—8-24
© 1999, Cisco Systems, Inc.
Source Dest. Seq. Ack.
TCP Windowing
Sender
Receiver
© 1999, Cisco Systems, Inc.
ICND—8-17
TCP Simple Acknowledgment
Sender Send 1 Receive ACK 2 Send 2 Receive ACK 3 Receiver Receive 1 Send ACK 2
Receive 2
Send ACK 3
Window size = 1
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-18
TCP Simple Acknowledgment
Sender Send 1 Receive ACK 2 Send 2 Receive ACK 3 Send 3 Receiver Receive 1 Send ACK 2
Receive 2
Send ACK 3
ICND—8-22
TCP Sequence and Acknowledgment Numbers
Source Port Dest. Sequence Acknowledgement Port # # …
I just sent #11.
I just got #10, now I need #11.
Source Dest. Seq. Ack. 1028 23 10 1
www.cisco.com
ICND—8-25
TCP Windowing
Window size = 3 Send 1 Window size = 3 Send 2 Window size = 3 Send 3
Receive 2
Send ACK 3
Receive 3 Send ACK 4
Window size = 1
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-20
TCP Sequence and Acknowledgment Numbers
Source Port Dest. Port Sequence # Acknowledgement # …
*Used by the router
Physical
Application
Transport Internet Data Link
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-6
Transport Layer Overview
Application Transport
Source Port Dest. Sequence Acknowledgement Port # # …
I just sent #11.
I just got #11, now I need #12.
Source Dest. Seq. Ack. 1028 23 10 1
Source Dest. Seq. Ack. 23 1028 1 11
www.cisco.com
ICND—8-9
TCP Port Numbers
Source Port Dest. Port
…
Telnet Z
Host A
Host Z
SP
DP
1028
23
…
Dest. port = 23. Send packet to my Telnet application.
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-4
TCP/IP Protocol Stack
Application Presentation Session Transport Network Data Link Physical
5
7
6 5 4
3
Application
4
Transport
3
Internet
Port Numbers
Application Layer
F T P
T E L N E T
23 TCP
S M T P
D N S
T F T P
S N M P
R I P
21 Transport Layer
© 1999, Cisco Systems, Inc.
25
53
69
UDP
Fra Baidu bibliotek
161
520
Port Numbers
Chapter 8
Interconnecting Networks with TCP/IP
© 1999, Cisco Systems, Inc.
8-1
Objectives
Upon completion of this chapter you will be able to perform the following tasks:
20 Bytes
Reserved (6) Code bits (6)
Checksum (16)
Window (16)
Urgent (16)
Options (0 or 32 if any)
Data (varies)
© 1999, Cisco Systems, Inc.
www.cisco.com
ICND—8-8