IANA is an Internet Assigned Numbers Authority, an Internet number assignment agency. Responsible for IP address allocation planning and port definitions for TCP / UDP public services. The International Internet Agency Member Authority (IANA) is an IP address, domain name, and many other parameters used in the Internet. IP address, autonomous system members, and many of the daily responsibilities assigned by many top and secondary domain names are borne by the International Internet Registration Center (IR) and Regional Registry.
The port number can be divided into three scope: "known port", "registration port", "dynamic and / or dedicated port". "Known port" is a port from 0 to 1023. "Register Port" is a port from 1024 to 49151. "Dynamic and / or Special Port" is a port from 49152 to 65535. In theory, these ports should not be assigned to the service. "Known port" is allocated by IANA, and can only be used by the system (or root) process or privileged users in most systems. The port used in TCP [RFC793] is used to name the logical connection end of the long-term dialog. In order to provide a service to an unknown caller, the system defines a service contact port. Contact ports are sometimes referred to as "known ports". In order to use these ports as much as possible, UDP [RFC768] uses the same port assignment. The assigned port is only used with a small portion of the port number available. For many years, allocated ports have been in the range of 0-255. Recently, the range of allocated ports managed by IANA has been extended to 0-1023. The registration port number "Register Port" is listed by IANA, and can be used by a program that can be performed by a normal user process or a normal user on most systems. The port used in TCP [RFC793] is used to name the logical connection end of the long-term dialog. In order to provide a service to an unknown caller, the system defines a service contact port. IANA will register the usage of these ports to provide convenience to the community. In order to use these ports as much as possible, UDP [RFC768] uses the same port assignment. The "Registered Port" range is 1024-49151.
Within the IP address range, non-route address IANA (InternetssignedNumBersauthority) reserves a part of the address as a private IP address space, specifically used for internal local area networks, which are as follows:
Class IP address range network
A 10.0.0.0 --- 10.255.255.255 (length is equivalent to 1 Class IP address)
B 172.16.0.0 --- 172.31.255.255 (length equivalent to 16 consecutive Class B IP addresses)
C 192.168.0.0 --- 192.168.255.255 (length equivalent to 256 consecutive Class C) IP addresses)
These addresses are not allocated by the Internet, so they have never been routed on the Internet, although they cannot be directly connected to the Internet, but still can be used to communicate with the Internet, we can use the appropriate address as needed. Class, boldly use these addresses as a public IP address in the internal local area network. On the Internet, those devices that do not need to communicate with the Internet, such as printers, manageable hubs, etc., can also use these addresses to save IP address resources.
Special IP address (reserved IP address)
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? We together look:
First, 0.0.0.0
Strictly speaking, 0.0.0.0 is no longer 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.
Three, 127.0.0.1
This 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.
Four, 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.
Five, 169.254.x.x
If your host uses the DHCP function to automatically get an IP address, then the WINGDOWS system will assign such an address for you when your DHCP server is faulty, or the response time is too long. 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 address, these addresses are largely used 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.
