India

IP ADDRESS

DNS

DHCP

India

IP Address

• What is an IP address ?

Internet protocol address

unique identifying number given to every single computer on the Internet.

IP address is a special serial number used for identification.

allows the machine to be located by other machines on the network

India

IP Address

• IP addresses can be either static or dynamic

Static IP – Fixed and never changes

Dynamic IP – temporary and could change

at any time

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IP Address

• Two Standards of IP address –

IPv4 – 32 bit binary bits 4 numbers separated by dots.

Example - 25.161.13.191

IPv6 – 128 bit binary bits eight groups of hexadecimal numbers separated by

colons(:).

Example - 2001:0db8:85a3:0000:0000:8a2e:0370:7334

India

IP Address

• IP address is divided in 2 parts :-Network ID and Host ID

Network ID – It’s a ID of the network and resembles the

network.

Host ID – It’s a identification of host on the network.

Net ID Host ID

Example – 25.161.13.191

India

IP Address Classes

India

IP Address

• IP Address classes –

Class Class Range Address Range Supports

Class A 0-126 10.0.0.0 to

10.255.255.255

16 million hosts on

each of 127 networks.

Class B 128-191 172.16.0.0 to

172.31.255.255

65,000 hosts on each

of 16,000 networks.

Class C 192-223 192.168.0.0 to

192.168.255.255

254 hosts on each of 2

million networks.

Class D 224-239 NA Reserved for

Multicasting

Class E 240-255 NA Experimental; used for

research

India

IP Address

• How to define network id and host id in IP

address classes ?10.12.34.10 :- 11001100.11100111.11111000.11001100

Class A –

First octet shows the network id and rest 3 octets shows the

host id.

Net Host

ID ID

2^24 16,777,216 hosts per network

10.12.34.10

India

IP Address

• How to define network id and host id in IP

address classes ?10.12.34.10 :- 11001100.11100111.11111000.11001100

Class B –

First 2 octets show the network id while the last 2 denotes

the host id.

Net Host

ID ID 2^16 16,384 hosts per network

10.12.34.10

India

IP Address

• How to define network id and host id in IP

address classes ?10.12.34.10 :- 11001100.11100111.11111000.11001100

Class C –

First 3 octets show the network id while the last 1 denotes the

host id.

Net Host

ID ID

2^8 256 hosts per network

10.12.34.10

India

LOOPBACK Address

India

IP Address

• Loopback address – (127.0.0.1)

Also called as Localhost.

Loopback has no hardware associated with it.

Allows us to test ip software without worrying about the broken or corrupted driver or hardware.

Loopback interface never goes down.

Used for management on routers.

India

APIPA Address

India

IP Address

• APIPA address – Link-local address

Automatic Private IP Address.

Range - 169.254.0.1 to 169.254.255.254

With APIPA, client machines can automatically self-configure an IP address.

Meant for small business environments, usually less than 25 clients.

ex. Home , small intranet LAN’s.

How to check if your computer is enabled for APIPA?

India

DNS

India

DNS

• DNS – Domain Name System

DNS is a protocol.

Used to translate a user friendly domain name into an IP address.

DNS implements a distributed database to store the name and

address information for all public hosts on the Internet.

DNS resolver – contacts DNS server to determine servers IP

address.

Best example of DNS is Internet.

India

DNS• How DNS works :- www.google.com

3. That’s in my cache.

It maps to IP address 70.42.251.42

5

DNS 4. great! I will cache

server 3 that for a while.

2

5.Thanks for

the direction DNS Server

4

1

1. I need direction to 2. The domain name is

www.google.com www.google.com is not

in my database

India

DHCP

India

DHCP

• DHCP :- Dynamic host configuration protocol.

Configures devices that are connected to a network so that they can communicate using the IP address.

Maintains database of available IP addresses and configuration information.

Allocate IP address to a client on a lease.

Lease :- amount of time that a given IP address will be valid for a computer.

Lease duration is set to 8 days by default.

DHCP Pool – contains list of available IP address.

India

DHCP

• How DHCP works :-

DHCP works on DORA process.

1) Discover

2) Offer

3) Request

4) Acknowledge

India

THE END