Categories IP address / IP address beginning with 10 and 172 the difference between the beginning and the beginning of the 192 / is determined whether the same network segment
In simple terms the company or companies see it basically within the network IP, ABC three types of IP addresses in the common IP segment.
Each IP address consists of two parts, i.e., the network number and host number.
InterNIC The IP address is divided into five categories:
A category reserved for ZF or large enterprises,
Class B allocated to the medium-sized companies,
class C is assigned to a small company or individual,
class D for multicast,
E class used in the experiment,
note : the number of different kinds of addresses that can be accommodated.
Wherein A, B, C three IP addresses: When the IP address written in binary form,
the first one is always the address O A type, such as, 10.0.0.1 00001010-00000000-00000000-00000001 ==
== "1.0 .0.0-127.255.255.255 default subnet mask 255.0.0.0, can accommodate up 16777215 computer
first two class B addresses are always 10, such as, 172.16.0.1 10101100-00010000-00000000-00000001 ==
== "128.0.0.0-191.255.255.255 default subnet mask 255.255.0.0, can accommodate up to 65,535 computers
top three class C address is always 110. Such as, 192.168.0.1 11000000-10101000-00000000-00000001 ==
== "192.0.0.0-223.255.255.255, default subnet mask 255.255.255.0, computers can accommodate up to 254
IP addresses reserved addresses: the host part of the IP address are all 0 is reserved for the network address, the host part of an IP address are all reserved as a broadcast address, multicast and retained as part 224--255 experimental purposes. Also note that IP address can not be 0 and the last bit address 255 is the allocation, because it is the broadcast address can not be used on an ordinary computer, but can be used on the gateway and router.
Private IP Address: is our common network segment to IP in three categories address.
10.0.0.0--10.255.255.255
172.16.0.0--172.31.255.255
192.168.0.0--192.168.255.255
Computer within the network to NAT (network address translation) protocol to access the Internet through a common gateway. The computer network may send a connection request to the other computers on the Internet, but other computers on the Internet can not send connection requests inwardly computer network.
Host Address species
Overview
to distinguish different categories by the leading bit (MSB) of the IP address of the IP address:
Note: n-bit network ID, h is host number bits
Class A addresses
Class A addresses: 0nnnnnnn.hhhhhhhh.hhhhhhhh.hhhhhhhh
Class A addresses having a network number 7, thus define class A network 126 {2 ^ 7-2 (network ID of all 0s or all 1s Note 1) 1 (loopback address 127 Note 2)} each the network may have a number of hosts is 16,777,214 {2 ^ 24-2 (host bits all 0s or all 1s)}
It represents a decimal range: 1.0.0.1-126.255.255.254, 0-127 any network addresses are a class A address.
Class B addresses
Class B addresses: 10nnnnnn.nnnnnnnn.hhhhhhhh.hhhhhhhh
Class B addresses having a network number 14, thus define 16382 Class B networks 14-2 ^ {2}
Each network may have a number of hosts 65534} {2 ^ 16-2
Represents a decimal range: 129.0.0.1-191.255.255.254, any 128-191 network address is a class B address.
Class C addresses
Class C Address: 110nnnnn.nnnnnnnn.nnnnnnnn.hhhhhhhh
Class C network address is a 21-bit number, it can be defined 2,097,152 Class C addresses 2 ^ {21-2}
Each network may have a number of hosts 254 is 2 ^ {8-2}
Represents a decimal range: 192.0.0.1-223.255.255.254, any 192-223 network address is a Class C address.
Class D addresses
Class D address: 1110xxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx
Class D multicast address is used, the front guide 1110 4, 28 behind the multicast address ID.
Decimal representation range: 224.0.0.0-239.255.255.255
Class E addresses
Class E addresses: always four guide 1111
Class E addresses are used for research use
Decimal representation range: 240-
Unified IP address assigned by the InterNIC (Internet Information Center), in order to ensure the uniqueness of the IP address, but there is a class IP addresses are not directly apply for the intranet, which is the Private Address, Private Address will not be on the INTERNET any routers forward, INTERNET to access must pass NAT / PAT transformation of public IP access in the form.
These private address is:
10.0.0.0-10.255.255.255 (a class A address)
172.16.0.0-172.31.255.255 (16 Class B addresses)
192.168.0.0-192.168.255.255 (256 Class C addresses)
Any one of the first octet network addresses between 224 to 239 is a multicast address
Any private IP network can be used include:
A Class A address (10.0.0.0),
16 Class B addresses (from 172.16.0.0 to 172.31.0.0)
256 Class C addresses (from 192.168.0.0 to the 192.168.255.0)
Subnet mask prefix notation! 1,111,111,111,111,111 111,111,100,000,000 24 turn into a composition equal to decimal 255.255.255.011111111 111,111,111,111,111 1111110030 composition 1-converted into a decimal equal to 255.255.255.252
Room always made a similar 10.0.0.1/29 or 10.0.0.1/28 or 10.0.0.1/30 or 10.0.0.1/27 address to us, for people who are not familiar with the network, it really baffling. What are the available IP in the end there? What gateway, subnet mask, broadcast address?
"/ 24" indicates that the IP subnet is 24, the subnet mask, refers to 24 "1", that is "255.255.255.0".
Four 8-bit subnet mask is a binary number consisting of 10 hexadecimal is changing into this right now, such as 255.255.255.0, into binary word is 1,111,111,111,111,111 1,111,111,100,000,000, a front 24, that is ip / 24,10.10.1.1 / 24, it says ip is 10.10.1.1, the subnet mask is 255.255.255.
Network ID is 10.10.10.0,24 expressed subnet mask of 255.255.255.0 is the IP network available bit 10.10.10.1-254
