ccna1 m9 tcp ip and ip addressing

8/14/2019 Ccna1 m9 Tcp Ip and Ip Addressing

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CCNA Semester1

Module 9TCP/IP and IP Add re ss in g

Objectives

Introduction to TCP/IP Internet addresses Obtaining an IP address


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Introduction to TCP/IP

History and Future of TCP/IP

The U.S. Department of Defense(DoD ) created the TCP/IPreference model because itwanted a network that could

survive any conditions. In 1992 the standardization of a

new generation of IP, IPv6 , wassupported by the InternetEngineering Task Force (IETF)with 128 bits long.


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Application Layer

Handles high-levelprotocols , issues ofrepresentation, encoding,and dialog control.

The TCP/IP protocol suitecombines all applicationrelated issues into one layerand ensures this data isproperly packaged beforepassing it on to the nextlayer.

Transport Layer

The transport layerprovides transportservices including flowcontrol and reliabilityfrom the source host tothe destination host.

The transport layerconstitutes a logicalconnection betweenthe endpoints of thenetwork.


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Other Internet Layer Protocols

Internet Control Message Protocol (ICMP)provides control and messaging capabilities .

Address Resolution Protocol (ARP) determinesthe data link layer address, MAC address, forknown IP addresses.

Reverse Address Resolution Protocol (RARP)determines IP addresses when the MAC addressis known.

Network Access Layer The network access

layer is also called thehost-to-network layer.

Include the LAN andWAN technology

details such as:Ethernet, Token-Ring,ISDN, Frame-Relay.

Include the mapping ofIP addresses tophysical hardwareaddresses andencapsulation of IP

packets into frames.


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Internet

Two computers, anywhere in the world, followingcertain hardware, software, and protocolspecifications, can communicate reliably.

Internet Addresses


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Network and Host Addressing

IP address ishierarchical and hastwo parts: First part identifies the

network where the system isconnected.

Second part identifies thatparticular system on thenetwork.

IP Address Classes

IP addresses are divided into classes to definethe large, medium, and small networks.


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IP Address Classes

IP Address

The 127.0.0.0 network is reserved for loopbacktesting.

The Class D address class was created to

enable multicasting in an IP address. Amulticast address is a unique network addressthat directs packets with that destinationaddress to predefined groups of IP addresses.

A Class E address is reserved these addressesfor research.


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Reserved IP Address

Certain host addresses are reserved and cannotbe assigned to devices on a network. Network address Used to identify the network itself

Broadcast address Used for broadcasting packets toall the devices on a network

Network address

Network address provide a convenient wayto refer to all of the addresses on aparticular network or subnetwork.

Two hosts with differing network addressrequire a device, typically a router, in orderto communicate.

An IP address that ends with binary 0s in allhost bits is reserved for the networkaddress.


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Broadcast address

Broadcast goes to every host with aparticular network ID number.

An IP address that ends with binary 1s in allhost bits is reserved for the directedbroadcast address.

An IP address with binary 1s in all networkbits and host bits is reserved for the localbroadcast address.

Local broadcast address

STOP255.255.255.255


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Public IP Address

In order to connect to the Internet, everymachines must have its own public IP address .Public IP addresses are unique.

With the rapid growth of the Internet, public IPaddresses were beginning to run out. Newaddressing schemes are used so solve this: Classless interdomain routing (CIDR) IP version 6 (IPv6) Network Address Translation (NAT)

Private Address

Private networks can use private address to assign their machines inthe local network .

RFC 1918 sets aside three blocks of IP addresses for private, internaluse . Class A: 10.0.0.0 Class B: 172.16.0.0 172.31.0.0 Class C: 192.168.0.0 192.168.255.0

Connecting a network using private addresses to the Internetrequires translation (overloading) of the private addresses to publicaddresses. This translation is served by NAT


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Obtaining an IP address

Obtaining an IP Address


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Static Assignment of IP Addresses

Each individual devicemust be configured withan IP address.

Keep very detailedrecords , becauseproblems can occur onthe network if you useduplicate IP addresses.

Dynamic addressing

There are a some different methods that youcan use to assign IP addresses dynamically: RARP: Reverse Address Resolution Protocol. BOOTP: BOOTstrap Protocol.

DHCP: Dynamic Host Configuration Protocol.

IP


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Reverse Address Resolution Protocol

BOOTP IP

Network administrator creates a configuration file thatspecifies the parameters for each device. The administratormust add hosts and maintain the BOOTP database.

BOOTP packets can include the IP address, as well as the

address of a router, the address of a server, and vendor-specific information.


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Dynamic Host Configuration Protocol

Successor to BOOTP. Automatically allows a host to obtain an IP address

from an IP pool Use 4-steps IP registration and requires IP leased

time

DHCP Initialization Sequence

Broadcast request and discoverDHCP server

Offer IP address, DHCP serveraddress and Default Gatewayaddress

Request for the offered IPstatistics

Acknownledge the request,confirm registration


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Encapsulation

Address Resolution Protocol

In order for devices to communicate, thesending devices need both the IP addressesand the MAC addresses of the destinationdevices.

ARP enables a computer to find the MACaddress of the computer that is associatedwith an IP address.


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Address resolution protocol

ARP table in host

R A M R A M


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10.0.2.1A.B.C.1.2.3

10.0.2.9A.B.C.7.8.9

10.0.2.5A.B.C.4.5.6

AA BB CC

ARP operation

ARP Table:

?MAC

A.B.C.1.2.3

MAC

?IP

10.0.2.1IP

10.0.2.9 Data

10.0.2.1A.B.C.1.2.3

10.0.2.9A.B.C.7.8.9

10.0.2.5A.B.C.4.5.6

AA BB CC

ARP operation: ARP request

MACA.B.C.1.2.3

MACff.ff.ff.ff.ff.ff

IP10.0.2.1

IP10.0.2.9 What is your MAC Addr?


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10.0.2.1A.B.C.1.2.3

10.0.2.9A.B.C.7.8.9

10.0.2.5A.B.C.4.5.6

AA BB CC

ARP operation: Checking

MACA.B.C.1.2.3

MACff.ff.ff.ff.ff.ff

IP10.0.2.1

IP10.0.2.9 What is your MAC Addr?

T h a t

i s

T h a t

i s

m y I

P m

y I P

10.0.2.1A.B.C.1.2.3

10.0.2.9A.B.C.7.8.9

10.0.2.5A.B.C.4.5.6

AA BB CC

ARP operation: ARP reply

MACA.B.C.7.8.9

MACA.B.C.1.2.3

IP10.0.2.9

IP10.0.2.1 This is my MAC Addr


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10.0.2.1A.B.C.1.2.3

10.0.2.9A.B.C.7.8.9

10.0.2.5A.B.C.4.5.6

AA BB CC

ARP operation: Caching

ARP Table:

A.B.C.7.8.9 10.0.2.9

MACA.B.C.1.2.3

MACA.B.C.7.8.9

IP10.0.2.1

IP10.0.2.9 Data

ARP: Local Destination


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Internetwork communication

How to communicate with devices that are

not on the same physical network segment.

Default gateway

In order for a device to communicate with another device onanother network, you must supply it with a default gateway .

A default gateway is the IP address of the interface on therouter that connects to the network segment on which thesource host is located.

In order for a device to send data to the address of a device

that is on another network segment, the source device sendsthe data to a default gateway .

Default-Gateway


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Remote Destination

Packet forwarding

At layer 2, when encapsulating a frame, the host needsthe destination MAC address

The host will then compares IP address of source anddestination. If the destination is on another network, then it will encapsulate the

frame with the default-gateway MAC address. If the destination is on the same net work, then it will use the

destination MAC address Then it checks if the needed MAC address is in the ARP

table , if it is not proceed ARP request to find the neededMAC address


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Summary

Four layers of TCP/IP model IP address, IP address classes Network address and broadcast address Public address and private address IPv4 versus IPv6 Static addressing, RARP, BOOTP, DHCP ARP local and remote destination

ccna1 m9 tcp ip and ip addressing

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