IPv4 vs IPv6 a Complete Guide

Which is better IPv4 or IPv6? What’s the difference between them?? Let’s see:

IPv4 is the most widely deployed Internet protocol used to connect devices to the Internet.

It uses a 32-bit address scheme allowing for a total of 2^32 addresses (just over 4 billion addresses). In the tremendous growth of internet the devices connected to internet is increasing on daily basis! This makes the addresses run out eventually.

Hence forth a new and advanced addressing system was developed and deployed to overcome the outrun which is IPv6 an coexists with IPv4 for some time... 

Fig: IPv4 vs Ipv6 address limitations

IPv6 (Internet Protocol Version 6) is also called IPng (Internet Protocol next generation)

There are some major differences between the two:

	IPv4	IPv6
Address Size	32 bit	128 bit
Format	Decimal notation	Hexadecimal notation
Prefix (example)	192.149.0.0/24	3FFE:F200:0234::/48
Number of Addresses	2^32	2^128
Packet Size	576 bytes	1280 bytes
Address mask	Used to designate network from host portion.	Not used
Address types	Unicast address, multicast address, and broadcast address	Unicast address, multicast address, and Anycast address
Address Configuration	DHCP or manual config	DHCPv6/SLAAC(Stateless address auto configuration)
IP header	Variable length of 20-60 bytes, depending on IP options present.	Fixed length of 40 bytes..
Ports	TCP and UDP have separate port spaces, each identified by port numbers in the range 1-65535.	For IPv6, ports work the same as IPv4. Because these are in a new address family, there are now four separate port spaces. For example, there are two TCP port 80 spaces to which an application can bind, one in AF_INET and one in AF_INET6.

Other IPv6 advantages over IPv4:

No more NAT (Network Address Translation)

Auto-configuration

No more private address collisions

Better multicast routing

Simpler header format

Simplified, more efficient routing

True quality of service (QoS), also called "flow labeling"

Built-in authentication and privacy support

Flexible options and extensions

Easier administration (say good-bye to DHCP)

Risks:

Security device bypass via unfiltered IPv6 and tunneled traffic

Congruence of security policies in v4 and v6

Bugs in new code

Absence of NAT

Source: https://www.networkworld.com/article/2171504/tech-primers/biggest-risks-in-ipv6-security-today.html

Growth:

Fig: Growth of IPv6 from its development

Source: https://www.google.com/intl/en/ipv6/statistics.html

Interesting Facts about IPv6:

Complete transition from IPv4 to IPv6 might not be possible because IPv6 is not backward compatible.

Leading zeroes and sometimes Inline zeroes are also suppressed (Used to shorten the length)

Link local unicast addresses are easy to identify (Example: local unicast addresses always begin with FE80. Similarly, multicast addresses always begin with FF0x, where the x is a placeholder representing a number from 1 to 8)

Loopback address (0000:0000:0000:0000:0000:0000:0000:0001 or ::1)

You don't need a traditional subnet mask

Related Links of Sources and Articles Referred:

https://www.linkedin.com/pulse/difference-between-ethernet-tcpip-best-answers-rushi-shroff/

http://study-ccna.com/osi-tcp-ip-models/

https://photonics.gsfc.nasa.gov/tva/photonics/HiDataRate/gigaether.htm

https://www.cnet.com/how-to/how-to-pick-the-right-cables-for-your-home-network/

https://www.howtogeek.com/210326/not-all-ethernet-cables-are-equal-you-can-get-faster-lan-speeds-by-upgrading/

https://www.cnet.com/how-to/how-to-pick-the-right-cables-for-your-home-network/

https://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_61/rzai2/rzai2compipv4ipv6.htm#rzai2compipv4ipv6__compaddrpref

https://www.techopedia.com/definition/7407/gigabit-ethernet-gbe

https://www.techrepublic.com/blog/10-things/10-things-you-should-know-about-ipv6-addressing/