IP Address: the network address plus the host address.
IPV4 address Category:
Class A: 8-bit network address, the host address 24
Class B: 16 bit network address, 16-bit host address
Class C: 24 bit network address, the host address 8
Class D: start with 1110. Representative octet 224-239 (denoted addresses for non-multipoint transmission)
Class E: The first 8 bits 4 bits 1111 of the front group. (Left unused)
Some important features of IP addresses
(1) IP address is an address structure of the sub-grade. Two grades
The benefits are:
First, IP address management agency distribution network numbers only in the allocation of IP addresses, while the remaining units to get host number by the number of self-distribution network. This facilitates the management of IP addresses.
Second, only the router in accordance with the network number of the destination host is connected to
Forwarding the packet (regardless of the destination host number), so that the number of items can be greatly reduced in the routing table, thereby reducing the storage space occupied by the routing table.
Third, connected by a bridge or repeater if one thousand Intranets
a network, so these LANs have the same network number of net-id.
Fourth, all assigned to the network number of the network net-id, a small range of
local area network, or may cover a large geographical range of WAN, are equal.
From the head unit is unable to determine the source host or network connected host whether a subnet IP datagram.
In the absence of relevant IP address subnet mask where there is no sense.
Network device IP address subnet mask determines which part of the network portion, which part is the host portion.
Given IP address and subnet mask of the IP address is located in claim calculating subnet network address, subnet broadcast address and IP address ranges can be used:
1. Set the IP address translation represented as a binary.
2. Convert the subnet mask into binary representation.
3. Draw a vertical line between 0 1 and the subnet mask, the left vertical position for the network, a host on the right vertical position.
4. The bits are all set to 0 the host, the network according to the write bit is the network address of the subnet.
5. The host bits are all set to 1, the network according to the write bit is subnet broadcast address.
6. interposed between the subnet broadcast address is the network address and subnet address range available IP subnet.
7. The first three paragraphs to write the whole network addresses.
8. represented as decimal conversion.