IP is a protocol standard with STD number 5. This standard also includes ICMP, and IGMP. The specifications for IP can be seen in RFC 791, 950, 919, and 992 with updates in RFC 2474. IP is also included in the internetworking protocol.
1. IP Addressing
An IP address is a representation of a 32-bit unsigned binary number. It is displayed in decimal form with dots. Example 10.252.102.23 is a valid example of an IP.
1.1. IP Address
IP addressing can be seen in RFC 1166 -- Internet Number. To identify a host on the internet, each host is given an IP address, or internet address. If the host is connected to more than 1 network, it is called multi-homed, which has 1 IP address for each interface. IP Address consists of:
IP Address = <nomer network><nomer host>Network numbers are regulated by an agency, namely the Regional Internet Registries (RIR), namely:
- American Registry for Internet Numbers (ARIN), responsible for North America, South America, the Caribbean, and sub-Saharan Africa
- Research IP Europeens (RIPE), responsible for Europe, the Middle East and parts of Africa
- Asia Pacific Network Information Center (APNIC), responsible for the Asia Pacific region.
IP address is a 32 bit binary number which can be written as a decimal number divided into 4 columns and separated by dots.
The binary number of the IP address 128.2.7.9 is:
10000000 00000010 00000111 00001001The use of IP addresses is unique, meaning that it is not permitted to use the same IP address in one network.
1.2. Class-based IP address division
The first bit of an IP address specifies the rest of the IP address. It can also separate an IP address from a network. Network. Network addresses are also known as netIDs, while host addresses are also known as hostIDs.
There are 5 classes of IP address division, namely:
Figure 4.1 Class Division in IP
Where:
- Class A: Uses 7 bits for network address and 24 bits for host address. This allows for 27-2 (126) networks with 224-2 (16777214) hosts, or over 2 million addresses.
- Class B: Uses 14 bits for the network address and 16 bits for the host address. This allows for 214-2 (16382) networks with 216-2 (65534) hosts, or about 1 million addresses.
- Class C: Uses 21 bits for network address and 8 bits for host address. This allows for 221-2 (2097150) networks with 28-2 (254) hosts, or about half a million addresses.
- Class D : This address is used for multicast
- Class E : Used for further use.
Class A is used for networks that have a very large number of hosts. While class C is used for small networks with less than 254 hosts. While for networks with more than 254 hosts must use class B.
1.3. The IP address you need to pay attention to
- Address with all bits = 0, used for network address. Example 192.168.1.0
- Address with all bits = 1, used for broadcast address. Example 192.168.1.255
Loopback address, the address with IP 127.0.0.0 is used as the loopback address of the local system.