interconnecting networks with tcp/ip · • identify ip address classes, ip addresses, ip subnet...
Post on 15-Aug-2020
13 Views
Preview:
TRANSCRIPT
© 2000, Cisco Systems, Inc. 8-1
Interconnecting Networks with
TCP/IP
Interconnecting Networks with
TCP/IP
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-2
Upon completion of this chapter you will be able to perform the following tasks:• 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.
ObjectivesObjectives
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-3
Early protocol suite
Universal
Introduction to TCP/IPIntroduction to TCP/IP
Host
Internet
TCP/IP
Host
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-4
TCP/IP Protocol StackTCP/IP Protocol Stack
7
6
5
4
3
2
5
4
3
2
Application
Presentation
Session
Transport
Network
Data Link
Physical1
Application
Transport
Internet
Data Link
Physical1
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-5
Application Layer OverviewApplication Layer Overview
*Used by the router
Application
Transport
Internet
Data Link
Physical
File Transfer- TFTP *- FTP *- NFS
E-Mail- SMTP
Remote Login- Telnet *- rlogin *
Network Management- SNMP *
Name Management- DNS*
File Transfer- TFTP *- FTP *- NFS
E-Mail- SMTP
Remote Login- Telnet *- rlogin *
Network Management- SNMP *
Name Management- DNS*
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-6
Transport Layer OverviewTransport Layer Overview
Transmission ControlProtocol (TCP)
User Datagram Protocol (UDP)
Transmission ControlProtocol (TCP)
User Datagram Protocol (UDP)
Application
Transport
Internet
Data Link
Physical
Connection-Oriented
Connectionless
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-7
Transmission control protocol Services:· Resource Utilization (multiplexing)· Connection Management (establishing) · Flow Control (Buffering / Windowing) · Reliable Transport (positive acknowledgment / error checking)
Transmission control protocol Transmission control protocol
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-8
Connection Management
The Transport Layer is responsible for establishing, maintaining and terminating connections between devices on a network. This Connection-Oriented Service has three phases:
Connection-Establishment
Data-Transfer
Connection Termination
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-9
Connection-EstablishmentConnection-Establishment
Phase 1 - Connection-Establishment: The source and destination negotiate a connection with a three-way handshake and a simple path between the two is determined.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-10
Phase 2 - Data-Transfer: Data is transmitted along the designated path of the network, arriving at the destination in the order it was sent.
Phase 2 - Data-Transfer: Data is transmitted along the designated path of the network, arriving at the destination in the order it was sent.
Connection-EstablishmentConnection-Establishment
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-11
Connection-EstablishmentConnection-Establishment
Phase 3 - Connection-Termination: The connection between the source and the destination is terminated when it is no longer needed. If they require additional communications after termination, another connection must be established.
Phase 3 - Connection-Termination: The connection between the source and the destination is terminated when it is no longer needed. If they require additional communications after termination, another connection must be established.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-12
TCP Port NumbersTCP Port Numbers
SourcePort
SourcePort
Dest.Port
Dest.Port ……
Host A
10281028 2323 ……
SP DP
Host ZTelnet Z
Dest. port = 23.Send packet to my
Telnet application.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-13
Send SYN (seq=100 ctl=SYN)
SYN received
Host A Host B
TCP Three Way Handshake/Open Connection
TCP Three Way Handshake/Open Connection
1
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-14
Send SYN (seq=100 ctl=SYN)
SYN received
Send SYN, ACK (seq=300 ack=101 ctl=syn,ack)
Host A Host B
SYN received
1
2
TCP Three Way Handshake/Open Connection
TCP Three Way Handshake/Open Connection
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-15
Send SYN (seq=100 ctl=SYN)
SYN received
Send SYN, ACK (seq=300 ack=101 ctl=syn,ack)
Established(seq=101 ack=301 ctl=ack)
Host A Host B
1
2
3
SYN received
TCP Three Way Handshake/Open Connection
TCP Three Way Handshake/Open Connection
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-16
TCP Simple AcknowledgmentTCP Simple Acknowledgment
Window size = 1
Sender Receiver
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-17
TCP Simple AcknowledgmentTCP Simple Acknowledgment
Window size = 1
Sender Receiver
Send 1 Receive 1
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-18
TCP Simple AcknowledgmentTCP Simple Acknowledgment
Window size = 1
Sender Receiver
Send 1 Receive 1
Receive ACK 2 Send ACK 2
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-19
TCP Simple AcknowledgmentTCP Simple Acknowledgment
Window size = 1
Sender Receiver
Send 1 Receive 1
Receive ACK 2 Send ACK 2
Send 2Receive 2
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-20
TCP Simple AcknowledgmentTCP Simple Acknowledgment
Window size = 1
Sender Receiver
Send 1 Receive 1
Receive ACK 2 Send ACK 2
Send 2Receive 2
Receive ACK 3Send ACK 3
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-21
TCP Simple AcknowledgmentTCP Simple Acknowledgment
Window size = 1
Sender Receiver
Send 1 Receive 1
Receive ACK 2 Send ACK 2
Send 2Receive 2
Receive ACK 3Send ACK 3
Send 3Receive 3
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-22
Window size = 1
Sender Receiver
Send 1 Receive 1
Receive ACK 2 Send ACK 2
Send 2Receive 2
Receive ACK 3Send ACK 3
Send 3Receive 3
Receive ACK 4 Send ACK 4
TCP Simple AcknowledgmentTCP Simple Acknowledgment
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-23
TCP Sequence and Acknowledgment Numbers
TCP Sequence and Acknowledgment Numbers
SourcePort
SourcePort
Dest.Port
Dest.Port
……Sequence#
Sequence#
Acknowledgement#
Acknowledgement#
Source Dest. Seq. Ack.
1028 23 10 1
I justsent #10.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-24
TCP Sequence and Acknowledgment Numbers
I just got #10,now I need #11.
SourcePort
SourcePort
Dest.Port
Dest.Port ……
Sequence#
Sequence#
Acknowledgement#
Acknowledgement#
10281028 2323Source Dest.
101010Seq.
11Ack.
102810282323Source Dest.
111111Seq.
11Ack.
I justsent #10.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-25
TCP Sequence and Acknowledgment Numbers
TCP Sequence and Acknowledgment Numbers
SourcePort
SourcePort
Dest.Port
Dest.Port ……Sequence
#Sequence
#Acknowledgement
#Acknowledgement
#
10281028 2323
Source Dest.
111111
Seq.
22
Ack.
10281028 2323Source Dest.
101010Seq.
11Ack.
102810282323Source Dest.
111111Seq.
11Ack.
I just got #10,now I need #11.
I justsent #11.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-26
TCP Sequence and Acknowledgment Numbers
TCP Sequence and Acknowledgment Numbers
SourcePort
SourcePort
Dest.Port
Dest.Port ……Sequence
#Sequence
#Acknowledgement
#Acknowledgement
#
10281028 2323
Source Dest.
111111
Seq.
101101
Ack.
10281028 2323Source Dest.
101010Seq.
100100Ack.
102810282323Source Dest.
111111Seq.
100100Ack.
102810282323Source Dest.
121212Seq.
101101Ack.
I just got #11,now I need #12.
I justsent #11.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-27
TCP WindowingTCP Windowing
Sender Receiver
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-28
TCP WindowingTCP Windowing
Window size = 3Send 2
Sender ReceiverWindow size = 3Send 1
Window size = 3Send 3
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-29
Window size = 3Send 2
TCP WindowingTCP Windowing
Sender Window size = 3Send 1
Window size = 3Send 3
ACK 3Window size = 2
Packet 3 isDropped
Receiver
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-30
Window size = 3Send 2
TCP WindowingTCP Windowing
Sender Window size = 3Send 1
Window size = 3Send 3
ACK 3Window size = 2
Packet 3 isDropped
Window size = 3Send 4
Window size = 3Send 3
Receiver
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-31
Window size = 3Send 2
TCP WindowingTCP Windowing
Sender Window size = 3Send 1
Window size = 3Send 3
ACK 3Window size = 2
Packet 3 isDropped
Window size = 3Send 4
Window size = 3Send 3
ACK 5Window size = 2
ReceiverWindow size = 3
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-32
udpudp
UDP is a TCP/IP Transport Layer protocol designed for applications that provide their own error recovery process. It trades reliability for speed. UDP is simple and efficient, but not reliable. UDP is connectionless and unacknowledged.UDP depends on upper layer protocols for reliability.Although UDP is responsible for transmitting messages, no software checking for segment delivery is provided at this layer.
The UDP header length is always 64 bits. Examine the field definitions of the UDP segment below by moving your mouse over each area. (View info without mouseover):
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-33
No sequence or acknowledgment fields
UDP Segment FormatUDP Segment Format
Source port (16) Destination port (16)
Length (16)
Data (if any)
1Bit 0 Bit 15 Bit 16 Bit 31
Checksum (16)
8Bytes
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-34
Data is transmitted along the designated path of the network, arriving at the destination in the order it was sent.
Data is transmitted along the designated path of the network, arriving at the destination in the order it was sent.
UDP data transferring UDP data transferring
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-35
Internet Layer OverviewInternet Layer Overview
OSI network layer corresponds to the TCP/IP internet layer
Internet Protocol (IP)
Internet Control MessageProtocol (ICMP)
Address ResolutionProtocol (ARP)
Reverse AddressResolution Protocol (RARP)
Internet Protocol (IP)
Internet Control MessageProtocol (ICMP)
Address ResolutionProtocol (ARP)
Reverse AddressResolution Protocol (RARP)
Application
Transport
Internet
Data Link
Physical
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-36
IP DatagramIP Datagram
Version(4)
Destination IP Address (32)
Options (0 or 32 if any)
Data (varies if any)
1Bit 0 Bit 15 Bit 16 Bit 31
HeaderLength (4)
Priority & Typeof Service (8) Total Length (16)
Identification (16)Flags
(3) Fragment offset (13)
Time to live (8) Protocol (8) Header checksum (16)
Source IP Address (32)
20Bytes
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-37
Determines destination upper-layer protocol
Protocol FieldProtocol Field
TransportLayer
InternetLayer
TCP UDP
ProtocolNumbers
IP
176
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-38
Internet Control Message Protocol
Internet Control Message Protocol
Application
Transport
Internet
Data Link
Physical
Destination Unreachable
Echo (Ping)
Other
ICMP1
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-39
Address Resolution ProtocolAddress Resolution Protocol
Used to resolve or map a known IP address to a MAC sublayer address to allow commnication on a multi-access medium such as Ethernet. To determine a destination address for a datagram, the ARP cache table is checked. If the address is not in the table, ARP sends a broadcast looking for the destination station. Every station on the network receives the broadcast.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-40
Reverse ARPReverse ARP
On the local segment, RARP can be used to initiate a remote operating system load sequence. ARP and RARP are implemented directly on top of the data link layer.Dynamic Host Configuration Protocol (DHCP) is a modern implementation of RARP. DHCP provides a mechanism for allocating IP addresses dynamically so that addresses can be reused when hosts no longer need them. For more information on DHCP, refer to the Building Cisco Remote Access Networks (BCRAN) course.
© 2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a—8-41
Do not deleteDo not delete
top related