Special IP Address Introduction Edit - Albert Source - China Agreement Analysis Forum Time - 2004-6-21
Just like each of us having an ID number, each computer in the network (more precisely, the network interface of each device) has an IP address to indicate yourself. We may all know that these addresses consist of four bytes, expressed in duty decimal, and their A, B, C classification, etc., however, in the total number of more than $ 100 billion, you know some common below. Is there a special sense of meaning? Let's take a look: 1, 0.0.0.0 Strictly, 0.0.0.0 is not a true IP address. It represents such a collection: all unclear hosts and destination networks. The "unclear" here refers to how to reach how to arrive in the routing table of this unit. For this machine, it is a "shelter", all "three no" personnel who don't know, will be sent in. If you set the default gateway in the network settings, the Windows system automatically produces a default route from 0.0.0.0. Second, 255.255.255.255 Limit the broadcast address. For this machine, this address refers to all hosts in this network segment (the same broad demand domain). If you translate into a human language, it should be like this: "Everyone in this room pays attention!" This address cannot be forwarded by the router. Third, 127.0.0.1 This unit address is mainly used for testing. Expressed in Chinese is "I myself." In the Windows system, this address has an alias "localhost". Addressing such an address, you can't send it to the network interface. Unless an error, the destination address should never have a packet of "127.0.0.1" in the transmission medium. Fourth, 224.0.0.1 multicast address, pay attention to it and the difference between broadcast. Such addresses are from 224.0.0.0 to 239.255.255.255. 224.0.0.1 Specific refers to all hosts, 224.0.0.2 specifically refer to all routers. Such addresses are used in some specific programs and multimedia programs. If your host opens IRDP (Internet Route Discovery Protocol, using the multicast function) function, then your host routing table should have such a route. 5, 169.254.xx If your host uses the DHCP function to automatically get an IP address, then when your DHCP server is fault, or the response time is too long, the WINGDOWS system will assign you such a address. If you find that your host IP address is an address such as this, unfortunate, ten eight nine is your network that cannot be running normally. Six, 10.x.x.x, 172.16. x. X ~ 172.31. x. X, 192.168. x. X Private addresses, which are used in large quantities in the enterprise internal network. Some broadband routers often use 192.168.1.1 as the default address. Private networks may use a free IP address because it is not interconnected with an external interconnection. Keeping such an address for use to avoid the address confusion when accessing the public network. When you use a private address, you want to use address translation (NAT) to translate private addresses into public legal addresses. On the Internet, this type of address cannot appear. For hosts on a network, it can have three legal destination network addresses: this machine's IP address, broadcast address, and multicast address.
