IP address v4 & v6 - Easy and quick to understand

 

In this session, we will learn more about IP address v4/IPv6. The identifier used by the IP layer in the TCP/IP protocol collection to distinguish each device connected to the Internet is called an Internet address or IP Address.

 

 

1. IP Address v4

 

 

- Size: 32 Bit (23232 = approximately 4.3 billion)

- All depleted in 2011.

- Class A, B, C, D, E

 

A Class (0 to 127): Common bit class with the first bit '0'

0.0.0.0 to 127.255.255.255 Default Subnet Mask: 255.0.0.0000000

01111111 IP address per network ID: 22424 (16,777,216)

 

 

B Class (128-191): Common bit class with the first bit '10'

128.0.0.0 to 191.255.255.255 Default Subnet Mask: 255.255.0.0 100000

10111111 Number of IP addresses per network ID: 21616

 

 

C Class (192~223): Common bit class with the first bit '110'

192.0.0.0 to 223.255.255.255 Default Subnet Mask: 255.255.255.011000

11011111 Number of IP addresses per network ID: 288

 

 

D Class : Multicast Address

224.0.0.0 to 239.255.255.255 Default Subnet Mask: X

111 00000 111 01111

 

 

E Class : Address reserved for IANA spare

240.0.0.0 ~ 255.255.255.255

 

 

When writing IP Address, the value of each Byte is expressed as a decimal number, and the total is 4 Byte, so the four decimal numbers are separated into (octets) as in 164.124.116.5

 

The range of values that 1Byte can represent is from 0 to 255, so the decimal number of each digit can be from 0 to 255, so you can say that the IP Address ranges from 0.0.0.0 to 255.255.255.255

 

 

 

 

 

 

 

 

2. Private IP Address

 

 

- A private IP address is an IP created for easy internal LAN use.

 

- IP addresses that are not Public on the Internet and are used arbitrarily for private purposes

 

 

A Class : 10.0.0.0 ~ 10.255.255.255 (10.0.0.0/8)

 

B Class : 172.16.0.0 ~ 172.31.255.255 (172.16.0.0/12)

 

C Class : 192.168.0.0 ~ 192.168.255.255 (192.168.0.0/16)

 

 

Private IP usually uses the above IP. If we're checking the IP, and we're using a band of low-level IPs, that means we're using a private IP, not an Public IP. For those who have IT, please memorize it.

 

 

Um... I don't know if you understand this if it's easier to explain, but the official IP Address is the only unique home address in the world, right?

 

 

Then, is the private IP address easily used in my house? Is it convenient to separate the living room, living room, kitchen, and bathroom? 192.168.10.0/24, living room 192.168.20.0/24, kitchen 192.168.30.0/24

 

 

If the master bedroom and the living room communicate in this way, then 192.168.10.0 <==> 192.168.20.0 is internally communicated.

 

 

Even if you use 192.168.10.0 in House A and 192.168.10.0 in House B, there will be no problem in communicating with this address internally (because it only goes back and forth from my house without going to someone else's house), right? However, the downside is that there is no external communication.

 

 

Gildong sent a letter to Brian's house in the U.S. with the address "Living Room." So when Brian gets the letter and addresses it back to Gildong's, wow, there's a "living room" in every house, where will it be sent? Of course, there's no communication.Lol I'm not sure if you'll understand it easily if you look at it like this.

 

Private IP is an IP address used only inside the same LAN. In order to communicate with the outside (Internet), communication can only be achieved by converting to a unique address (public IP) worldwide. Keep this in mind.

 

 

[Why Private IP?]

 

1) To replace insufficient IP Address - to replace insufficient IP because IPv4 is already depleted

 

2) Strong security from the outside - private IP is not accessible from the outside.

 

 

 

 

3. IPv6 Address

 

 

Address representation method

 

- 128 bits divided into 16 bits, expressed in hexadecimal, separated by ':'

- 16bit : 16bit :16bit : 16bit : 16bit : 16bit : 16bit : 16bit

HHHH : HHHH : HHHH : HHHH : HHHH : HHHH : HHHH : HHHH

 

- If '0' continues, it can be condensed to '::' (but can only be used once within the address)

 

- If the entire 16 bits are '0', it can be saved as '0' (the '0' in the front part can be omitted)

 

▶ Unicast: Identifier for a single interface used in 1:1 communication methods

 

▶ Multicast : 1:N communication method includes both IPv4 broadcast and multicast method

 

▶ Anycast: Served by the nearest equipment providing the same service

 

 

 

 

 

[Why IPv6?]

 

1. Troubleshooting IPv4 address depletion

 

2. Security Features

 

3. Routing efficiency

 

4. QoS guarantees

 

5. Convenient Internet service functionality, mobility

 

※ How to switch from IPv4 to ipv6

 

It is impossible to change all equipment in the world to IPv6 overnight. So how do you run ipv4 and IPv6 as a mixed network? There are three ways.

 

 

 

1) DualStack

- It is a technology that enables both IPV4 and IPv6 to be used in devices, operating systems, and applications, and can handle either of them. This is the most common approach for IPv6 transitions.

 

 

2) Tunneling

- Early in the IPv6 transition, there are more IPv4 networks. If there are IPv6 terminals at both ends and the IPv4 network is blocked on the intermediate path, a logical tunnel path is configured in the IPv4 network to allow IPv6 communication between the two ends by wrapping IPv6 packets in an IPv4 header, passing through the IPv4 network, and peeling the IPv4 header again just before the destination.

 

Tunneling technology is very useful as a technology beyond the IPv4 only network when dual stacks are difficult to apply across all sections of the network.

 

 

3) Translation

- IPv6 => Completely recombine packets to IPv4 or vice versa. Since there is a limit to reflecting all the characteristics of each communication application, it is recommended to be used only for limited sales during the IPv6 transition period.

 

This time, we learned about v4 and v6 in IP Address and how to move on. But I don't know when the v6 will be used as a standard yet. Let's learn more about the current ipv4 in detail.

 

 

 

 

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