The core concept of
IP Address: identifies the host (interface) , where the host network type,
subnet mask: Network address (network ID + subnet number) and the host address
* IP Address + Subnet Mask: subnet ID (identification subnet ), each network number of subnets, each subnet size (ip range)
IP address of the network number + = + host number subnet number
network number is identified by a network: 202.183.0.0
subnet number is identified in a subnet a network (LAN) 202.183.3.0
host is identified by a number within the network in a subnet a host 202.183.3.12
IP address that identifies a host (interface) within a network, a subnet
Network type
according to how much of the network host (size of the network), the network is divided into three categories A, B, C
A number of hosts in the network up to class (long host ID, 24): 16 million per network hosts, but A small number of network-based network
B (128) class: 6503
C (192) categories: 253
Subnetting
master when a network (public network) many that are scattered within a larger geographic location, this may be a network (public network) is divided into several host belongs to the subnet (LAN), then each subnet (Local Area Network) interconnection between routers with
each subnet with a subnet number to identify the division.
Determining the number of subnets in the subnet division number (bits)
, such as: a unit to assign a class C IP address for the host 202.114.16.0 added 5 units of subnets to be divided, 5 converted to binary 101, so. represented by three binary subnet field. If the host is to be divided into two subnets, converted to binary 2 to 10, so use two binary representation of the subnet field. To be divided into nine it, like, 9 is converted to binary is 1001, you need four binary representation of the subnet field (divided into four sub-borrowing host number two as a subnet number: 00, four subnets, borrow three division 6)
Subnet Mask effect: extracting a network address of the subnet, there is determined for several subnets, judging whether the host within a sub-network, extracts the host address of the destination host IP subnet based on the destination host IP address (subnet router the basic unit facing forward, instead of a single host) is a router device connected to the network, the end system is not connected to a device
Network Number - Type Network - Network size (the maximum number of hosts)
the determined network number, determines the size of the network
Subnet number - subnet number of bits - the number of subnets
How do I know if a subnetting? How many subnetting advantage?
+ Subnet number network number - Subnet Mask
The subnet mask three forms:
202.15.43.0 \ 24-
11111111 11111111 11111111 1000
255.255.254.0
Complete the process of
the destination host IP address
172.32.7.112 = 10101100 00100000 00000111 01110000
network where the destination host subnet mask:
255.255.254.0 = 11111111 11111111 11111110 00000000
Analyzing the initial
destination network: IP address before the 8-bit 172, the class B network, the network number for the first 16 bits
subnet number digits: Subnet Mask = 254 + 27 + 26 ... 21, No. 7, by the host as a subnet number
before it is an object network 23 is a network address (network number + subnet number)
Two attribute values can be obtained:
1. Both a "and" operation (an all-1, 0 otherwise) to give
sub-network address of the destination host resides
101,011,000,010,000 0,000,011,000,000,000
into decimal point to give (27 + 25 22.25.2 + 22.0 + 23 +):
172.32.6.0
7 subnet number: 172.32 So class B network 128 is divided into 27 sub =
9 host number: = 29 so each subnet 512 IP address
network range: 255 (total length) / 128 (the number of subnets) = 2 (length of each subnet)
172.32.6.0 -172.32.7.255
Note: 172.32.0.0 represents both the network number is 172.32 public network, also said 172.32.0.0 subnet (local area network)
Overall process:
Internet network is divided into a number, divided into A (1600w), B (6500 ), C (255) the size of the network according to the three types, each type has its own IP range section (dichotomy: 128, 192 )., each network identified by network ID. Each network has been divided into many sub-network, basic transmission object-oriented subnets that router.
Internet - Network - Subnet (Router) - host four-layer structure
