Unit05

Unit05:

IP Addressing

Overview

• IP

• Assigning IP Addresses

• Creating a Subnet

• IPv6

IP Addresses

IP Address192.168.1.180IP Address

192.168.1.180

IP Address192.168.2.182IP Address

192.168.2.182

IP Address192.168.2.180IP Address

192.168.2.180IP Address

192.168.2.181IP Address

192.168.2.181

IP Address192.168.1.182IP Address

192.168.1.182

IP Address192.168.1.181IP Address

192.168.1.181

IPv4

• Each IP address is composed of two portions – one that identifies the network – the other that identifies the host

• Class A addresses have a first octet value between 1 and 126.

• Class B addresses have a first octet value between 128 and 191. The addresses beginning with 127 are reserved for loopback testing. You can test this by pinging 127.0.0.1 on any computer.

• Class C addresses have a first octet value between 192 and 223

Classes of IP Addresses

Class CNetwork ID Host ID

1 1 0

xw y z

Class BNetwork ID Host ID

1 0

xw y z

Class ANetwork ID Host ID

0

xw y z

Dotted Decimal Notation

11 11 11 11 11 11 11 11

8 Bits

255 Decimal Value

128128 6464 3232 1616 88 44 22 11

Subnet

Subnet 1131.107.10.0

Main network131.107.12.0

Subnet 2131.107.3.0

131.107.10.12131.107.10.12

131.107.12.31131.107.12.31

131.107.3.27131.107.3.27

131.107.12.7131.107.12.7

Using CIDR

220.78.175.0

220.78.168.0

Subnet mask Subnet mask (binary)Network ID

11011100 0100111010101000 00000000

Starting network ID

11011100 0100111010101111 00000000

Ending network ID

Class C ExampleClass C Example

255.255.248.0

Subnet mask Subnet mask (binary)Network ID

11111111 1111111011111000 00000000

220.78.168.0

CIDR EntryCIDR Entry

Guidelines for IP Addressing

When assigning network and host IDsWhen assigning network and host IDs

Do not use 127 for a network IDDo not use 127 for a network ID

Do not use all 1’s for network and host IDDo not use all 1’s for network and host ID

Do not use all 0’s for the network IDDo not use all 0’s for the network ID

Use a host ID that is unique to the local network IDUse a host ID that is unique to the local network ID

IPv6

• Internet Protocol version 6 (IPv6) was designed by the Internet Engineering Task Force (IETF) to overcome the limitations of IPv4 addresses

• An IPv6 address is 128 bits in length • Example : 402A:0:2F7C:1:8BB:FFE3:728D:95A

IPv6• Unicast

– addresses identify a single interface and are used when a single host sends a message to another single host.

• Multicast – addresses identify multiple interfaces when a single host is sending

messages to many hosts.• Anycast

– addresses identify a single interface among many interfaces and are used when a single host sends a message to the nearest interface available.

• Site-local – addresses are available to any private network to use internally without the

need to register the address. They are used for networks that aren’t connected to the Internet, or for networks that aren’t directly reachable because of a firewall.

• The loopback – address is 0:0:0:0:0:0:0:1 (also written as ::1). Loopback addresses identify

a logical loopback interface, which allows the node to send packets to itself for testing purposes

Default Gateways

• Default gateway is an IP address of a router that is designated for any traffic for which the route is unknown

• When a network router receives data, and it has an address for a default gateway, it follows this process:

– The router looks at the IP header to determine the destination IP address.

– The router determines whether the destination IP address is on the same network segment the data was received from.

– If the destination IP address is for a different network, the router looks in its routing table for a route to that address.

– If the router does not have a route listed for that destination network, it selects the default gateway address.

Public and Private IP

Public addressesPublic addresses

Private addressesPrivate addresses

Do not have to be registered

Can be assigned by the network administrator

Are used on computers that are not accessed by the Internet 10.x.y.z 172.16-32.x.y 192.168.x.y

Do not have to be registered

Can be assigned by the network administrator

Are used on computers that are not accessed by the Internet 10.x.y.z 172.16-32.x.y 192.168.x.y

Are assigned by an ISP

Consist of unique class-based blocks

Are kept to a limited number

Are assigned by an ISP

Consist of unique class-based blocks

Are kept to a limited number

TCP/IP Protocol Functions

• ICMP

• FTP

• ARP

• DHCP

• RARP

• DHCP

ICMP

• Internet Control Message Protocol (ICMP)

• An Internet layer protocol that reports on the success or failure of data delivery

• ICMP announcements provide critical information for troubleshooting network problems

ARP

• Address Resolution Protocol (ARP)

• An Internet layer protocol that obtains the MAC (physical) address of a host, or node, then creates a database that maps the MAC address to the host’s IP (logical) address

RARP

• Reverse Address Resolution Protocol (RARP)

• Allow the client to send a broadcast message with its MAC address and receive an IP address in reply

• RARP was originally developed as a means for diskless workstations

DHCP

• Dynamic Host Configuration Protocol (DHCP)

• An automated means of assigning a unique IP address to every device on a network

• DHCP does not require a table of IP and MAC addresses on the server

• DHCP does require configuration of DHCP service on a DHCP server

TELNET

• A terminal emulation protocol used to log on to remote hosts using the TCP/IP protocol suite

• Using Telnet, a TCP connection is established and keystrokes on the user’s machine act like keystrokes on the remotely connected machine

• Telnet is notoriously insecure

FTP

•Used to send and receive files via TCP/IP

•FTP commands will work from your operating system’s command prompt

•Many FTP hosts accept anonymous logins