Internet & Address

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IANA

IANA stan for Internet Assigned Numbers Authority. U.S. Government Employee Jon Postell - Administering the ARPANET. Since then, Internet has grown rapidly. After that IANA functions are no longer managed by just one person. They are managed by ICANN (Internet Corporation for Assigned Names & Numbers). 
Function: When a device comes online, it needs to know how to talk to another devices that are also online. So each device has Unique Identifiers. ICANN manages Domain Names. 
Example: Google.com, Facebook.com etc.
This domain names links a specific IP Address.
            www.icann.org ..........
                Domain name
                        192.0.32.7 ..........
                             IP Address
IANA Works
When you visit a Website, you type Domain Name or click on HTML.
Doman name is sent to your server which translates the name into numbers called IP Address.
Server use to direct your request to Website location.
Those names and numbers are "Unique Identifiers" which align with Set of Protocol Parameter.
This is IANA  function which is managed by ICANN.

IP Address is Allocated

IP Address
Subnet Mask
Default Gateway
DNS Server
Manually: You need to go each computer asset to put a manually IP and subnet mask. Its better to keep network small. Static IP
Automatically:  It can be done through DHCP Server. Dynamic Host Configuration Protocol. Dynamic IP
IP Address: IP Address stand for Internet Protocol Address.

IPv4 Address

32 Bit Number (0 1)
Written in Decimal Digit (0-255)
It has Four 8 Bits Field called Octets
Referred as a Dotted-Decimal Format (01.10.1.11)
Binary value either be 0 or 1 digit. Each digit called a Bit. 8 Bit = 1 Byte or 1 Octet
Type of IPv4 Address
Network Parts 01.10.x.x
Host Parts x.x.1.11

IPv6 Address

128 Bit Number (0 1)
Written in Hexadecimal Digit (0-FFFF)
It has Y 8 Bits Field called Segment
Type of IPv6 Address
Normal IPv6  Y : Y : Y : Y : Y : Y : Y : Y   (Y  is called Segment. (0-FFFF))
Dual IPv6 + IPv4  Y : Y : Y : Y : Y : Y : X : X : X : X (Y is called Segment. (0-FFFF) X is called Octets. (0-255)). IPv6 servers running on a dual stack host accept connections from IPv4 and IPv6 client.

IP Address Detecting

Commands	Description
ipconfig	Windows
ifconfig	Linux and Other Operating System
arp -a	Detail of any system

Ping

Time taken for ICMP packets travelling between devices is measured by Ping.
Network Tool.
Used to check that target system is alive or not.
Uses ICMP protocol (Internet Control Message Protocol).
Example : Ping<ip/website>

Ping Works
Sends Echo Request.
Ping + Website URL's
Ping + IP Address

Ping Sweep
Ping Sweep is called as ICMP Sweep.
Uses Two Way Handshake Protocol.
Used to check the potential of IP address used by "Live" or "Dead".
Example : nmap -sn <ip>
Example : nmap -Pn <ip>

Check Multiple IP Address are alive or not

c:\Users\HR>cd "c:\Program Files (x86)\Nmap" (Nmap Location) c:\Program Files (x86)\Nmap>nmap --help c:\Program Files (x86)\Nmap>nmap -j c:\Program Files (x86)\Nmap>nmap -h c:\Program Files (x86)\Nmap>nmap -sn 192.168.56.1/24 (IP Address/24)

Check Detail of multiple IP Address

c:\Users\HR>cd "c:\Program Files (x86)\Nmap" (Nmap Location) c:\Program Files (x86)\Nmap>man | grep sn c:\Program Files (x86)\Nmap>nmap -sn 192.168.56.1/24 (IP Address/24)

Traceroute

Traceroute (Windows Operating System)

C:\Users\HRSIKH>tracert www.google.com

Linux Nmap Commands

Commands	Description
nmap -h	Details of Nmap

ARP Spoofing

ARP stand for Address Resolution Protocol.

Request goes through router gateway and coming form that way.

Gateway must know which request is need to deliver in which IP.

Gateway transfer an ARP packet across the network and every host write its IP and MAC address on it, then collects information and map IP with MAC.

Arp is used to map the IP with MAC or discover mac address.

Every host can also send ARP packet across network like router sends.

Then host make their own ARP table and make IP with own mac address.

Its called ARP poisoning.