01_tcp/ip Concept

1. IP Address

In the TCP/IP protocol stack, addressing is defined by the IP protocol. for IPv4, the IP protocol stipulates that each host has a 32-bit Host IP address, which is divided into two parts: <1> network number <2> host number.

Each physical network in the network has a unique value as the network number; each host in the network has a unique host number.

In addition to each host, the IP protocol assigns an IP address to each vro.

 

2. Address Resolution

Address Resolution (Address Resolution) is to translate the Protocol address (IP address) in the computer into a physical address (MAC code, also a media ing address). Address resolution can only be performed within the Internet.

Address Resolution technology:

<1> table-loopup: Applicable to the WAN. It is an array (Protocol address, MAC code) created ).

<2> closeform-computation (similar form calculation)

<3> message-Exchange: This method is applicable to lan and is a distributed processing method. A host sends a resolution request in the form of a broadcast and waits for the response from the host in the network. The ARP Protocol specifies the basic types of information: <1> request <2> response (response)

 

3. Domain Name System

In the TCP/IP protocol family, the domain name system is a distributed database that provides ing information between IP addresses and host names.

You can call a standard library function to view the IP address of the host with the given name. The system also provides an inverse function to view the corresponding host name for the given IP address.