A few special IP addresses

1) Private Address 　　
IP address is unique throughout the world, see this sentence you may have such a question, such as 192.168.0.1 address in many places can see, not the only, why? The Internet Management Committee stipulates that the following address is a private address, the private address can be used on its own network, but not on the Internet, Internet network does not have these addresses of the route, the computers have these addresses to the Internet must be converted into a legitimate IP address, also known as the public network address, It's like there are a lot of parks, each park can be named the same street, such as the Champs Elysees, but outside we can only see the address of the park and the real Champs Elysees.
The following are private address segments in a, B, Class C network.
You can use these addresses when you set up your own network.
10.0.0.0~10.255.255.255
172.16.0.0~172.131.255.255
192.168.0.0~192.168.255.255

2) loopback Address　　
Class A network address 127 is a reserved address for network software testing and inter-process communication between local machines, called Loopback addresses (loopback address). No matter what program, once send data using loopback address, the protocol software returns immediately without any network transmission.
Groupings with network number 127 cannot appear on any network.
"Little tricks."
Ping 127.0.0.1, if the feedback message fails stating that the TCP/IP stack is faulty, you must reinstall the TCP/IP protocol. If successful, ping the native IP address, if the feedback message fails, it means that your network card cannot communicate with the IP protocol stack.

3) broadcast address　　
TCP/IP specifies that the host number is a "1" network address for broadcast purposes, called broadcast address. Broadcast means sending messages to all hosts on the same subnet at the same time.

4) Network address　　
The TCP/IP protocol stipulates that all members of the "0" host number are interpreted as "this" network.
From the above can be seen:
(1) A packet with network number 127 cannot appear on any network;
(2) The host and gateway cannot broadcast any path finding information for this address.

As can be seen from the above provisions, the host number "0" full "1" address in the TCP/IP protocol has a special meaning, generally cannot be used as a host of valid address.

A few special IP addresses