Teach you to recognize network special purpose IP address

The internet is a global network of computers as a whole, composed of communication networks, in the case of two of computer tones on the Internet, some additional information is included in the packets they transmit, like the phone number we use, and every computer on the internet has its own "phone number". To mark yourself, this "phone number" is a network IP address, each IP address is a 32-bit binary array, and in the context of the Internet the address is unique. In order to facilitate the administrator to decorate the intranet, while leaving some special IP address, let us look at these IP address is what to do with it?

First, 127.0.0.1

127 is a reserved address, which refers to the computer itself, the main function is reserved for the test use, for network software testing and local machine interprocess communication. Under Windows System, the address also has an alias called "localhost", regardless of which program, once the address to send data, the protocol software will immediately return, without any network transmission, unless there is an error, the group containing the network number is not able to appear on any network.

Second, 10.*.*.*,172.16.*.*――172.31.*.*,192.168.*.*

The above three network segments are private addresses, can be used for their own networking, these addresses are mainly used in corporate internal networks, but not available on the Internet, Internet networks do not have these addresses, and computers using these three segments must go online through address translation (NAT), Translates a private address into a public legitimate IP address. Some bandwidth routers or other network devices, often using 192.168.1.1 as the default address, because private personal network will not be connected with the outside, so you can use arbitrary IP address, retain the IP address of these three segments to use, is to avoid later access to the public network caused address confusion.

Third, 0.0.0.0

Strictly speaking, 0.0.0.0 is no longer an IP address in real sense. It represents such a collection of all the unknown hosts and destination networks. The unclear here is that there are no specific entries in the local routing table indicating how to get there. For this machine, it is a shelter, all do not know the three without personnel, are sent in. If you set a default gateway in your network settings, the Windows system automatically generates a default route with a destination address of 0.0.0.0.

Four, 255.255.255.255

Restricted broadcast address, for this machine, this address refers to all the hosts within the network segment (the same broadcast domain), which is used for the destination address of the IP packet in the host configuration process, when the host may not know the network mask of its network, or even its IP address is not known. In any case, routers prohibit forwarding of packets with destination addresses that are restricted to broadcast addresses, and such packets will only appear on the local network.

Five, 224.0.0.0-239.255.255.255

This is a set of multicast addresses that need to be aware of the difference between it and the broadcast address, where 224.0.0.1 refers to all the hosts, 224.0.0.2 refers to all routers, 224.0.0.5 all OSPF router addresses, 224.0.0.13 the address of the PIMV2 router. In addition, the router is not forwarded from 224.0.0.0――224.0.0.255 only to the LAN, 239.0.0.0――239.255.255.255 is a private address (as with 192.168 *.* function), 224.0.1.0- 238.255.255.255 can be used on the Internet. If your host is on the IRDP (Internet Routing Discovery Protocol, use multicast function), then your host routing table should have such a route.

VI. 169.254.*.*

If your host uses DHCP to automatically obtain an IP address, then when your DHCP server fails or the response time is too long to exceed the system's allotted time, the Windows system assigns you such an address. If you find that your host IP address is a sort of address, it's unfortunate that your network is not functioning properly.