Brief introduction of several kinds of Special IP addresses

One, 0.0.0.0

Strictly speaking, 0.0.0.0 is no longer a true IP address. It represents a collection of all unknown hosts and destination networks. The "unclear" here means that there is no specific entry in the local routing table indicating how to get there. For this machine, it is a "shelter", and all the "three nots" people who do not know it will be sent in. If you set the default gateway in the network settings, the Windows system will automatically generate a default route with a destination address of 0.0.0.0.

II. 255.255.255.255

Restrict broadcast addresses. For the local machine, this address refers to all hosts in the local network segment (the same broadcast domain). If translated into human language, it should go something like this: "attention, everyone in this room!" This address cannot be forwarded by the router.

III. 127.0.0.1

Local address, mainly used for testing. In Chinese, it means "myself". In Windows

In the system, this address has an alias "Localhost". Addressing such an address cannot be sent to the network interface. Unless something goes wrong, it should never be done on the transmission media.

A packet with a destination address of "127.0.0.1" appears.

IV. 224.0.0.1

Multicast address, pay attention to the difference between it and broadcast. From 224.0.0.0 to 239.255.255.255

It's always the same address. 224.0.0.1 refers specifically to all hosts and 224.0.0.2 to all routers. Such addresses are often used for specific programs as well as multimedia programs. If your host turns on IRDP (Internet Route Discovery Protocol, using multicast), then you should have such a route in your host routing table.

5. 169.254.x.x

If your host uses the DHCP function to automatically obtain an IP address, the Wingdows system will assign such an address to you when your DHCP server fails, or the response time is too long to exceed a system-specified time. If you find that your host IP address is something like this, unfortunately, nine times out of ten, your network is not working properly.

VI. 10.x.x.x

172.16.x.x~172.31.x.x

192.168.x.x

Private addresses, which are widely used in the enterprise internal network. Some broadband routers also often use 192.168.1.1 as the default address. Private networks may use random IP addresses because they are not connected to the outside world. Such addresses are reserved for their use in order to avoid

It will cause address confusion when connecting to the public network in the future. When a private network accesses the Internet, it uses address translation (NAT) to translate the private address into a public legal address. On Internet, this kind of address cannot appear. For a host on a network, there are three kinds of legitimate destination network addresses that it can receive normally: the local IP address, the broadcast address and the multicast address.