Chapter L SARS System Introduction This chapter includes the following sections: • Domain name registration, resolution, and distribution. The domain name system (D n s) is a registered computer name and a directory of the I P address that can be locked. This section will outline an important part of D N S - name service, and how it is registered, parsing, and transmitting computer names. D N S servers can be used to locate services within the domains they are authorized. If the service location function is implemented, you can send a request for a computer but find a service in the domain, and you can get an I P address as an answer. Note: Windows 2000 requires the use of service records (S RV records will be mentioned later). • Characteristics of the host name. Whether it is preparing to naming a computer or planning to naming thousands of computers, D n s computer naming rules is very important. This section will introduce some necessary naming rules and provide some suggestions for your computer. • The whole domain name. The computer on I N t e R n e t is a member of a certain domain. This section will narrate the domain name, the whole domain name, and how they are formed. This book is a book that describes the domain name system, which is suitable for both newcom and skilled D n s administrators. This book also tells the new Windows 2000 DNS server and how to use D N S in Wi N D O W s. Reading this book does not require readers to have D N s's preparation knowledge, but readers with a certain background knowledge will likely find some new knowledge. This does not mean that the quality of the information provided in the book is problematic, nor does it mean that the reader's background knowledge is defective. The Windows 2000 operating system uses D n s different from Microsoft's previous operating system - in fact, it is also different from any of the previous operating systems. Although this book begins to analyze and explain D n s from the perspective of world generic standards, it ends with a complete review of Windows 2000 features. The intermediate part of this book discusses the use of Bind in Windows 2000, using Windows 2000 DNS, new D n s feature and focus in non-Wi N D O W s, and practices for D n s under the new interface. In the support of the Active Directory domain environment, D N s is in a center and use a large number of locations. When I ask 1 0 0 Windows 2000 configuration experts, which is the most important thing you can work correctly, almost 1 0 0 in the 1 0 0 item mentioned is D n s. The important features of the Wi N D O W S2 0 0 0 system are related to D n s from the daily behavior of the active directory to the user. The introduction of this book will start from D N S itself, look at it, it is how it works, and how it works and the time-related B i n D version or Windows 2000) how to use it. Finally, some features of the new version D N S are introduced, as well as items that should be noted when used in a Windows environment and how it is used. This chapter does not require a lot of preparatory knowledge when introducing the domain name system, just know how the computer works and how it is interacting with I n t e R n e t. Anyone who needs to understand D N S and D N s servers can obtain the necessary knowledge by reading this book. In this chapter, you can learn from a certain degree of details, what is the domain name system to understand the domain name system and D N S server to meet the needs of all local and worldwide computer users. 1.1 Domain Name Registration, Analysis, and Distribution I N T E R N e t on the computer on the computer is performed by the I P address. Therefore, the computer on i n t e R n e t should have an I P address as their unique identifier. The domain name system is used to register the computer name and its I P address. D N s is developed and developed in the I n t e R N e T environment, and the purpose is to make anywhere's host can find another computer through a relatively friendly computer name rather than its I P address.
D N S is a continuous development service that is continuously upgraded by the draft of the I N t e R N e T engineering task group (I f T f) and a recommendation called R f C (Request for Comment) file. These drafts and R f C files are introduced in the subsequent chapter of this book. Do not confuse domain system servers and domain name systems. Domain Name System Server is just a tool in a domain name system that implements the functionality of domain name system through them. This chapter will introduce the domain name system and domain system server, please pay attention to the difference between the two. The D n S server provides a client to store and search for host names and I P addresses from other hosts. The client can be a separate computer user, application server, and even other D n s servers. The host is another name of the computer, and the host name is the name used by the computer in the domain name system. Domain namespace refers to a unique and relatively friendly hostname consisting of all hosts on I N t e R n e t, which is an important concept. Each hostname and its I P address are stored in one or more D n s servers so that other users in I N t e R n e t can search for the I P address of the respective host through the computer name. To this end, a reliable communication must be performed between the D N S server to form a comprehensive system to form an integrated system. The domain tree is the skeleton of the domain name space, and the D n s servers can be moved around them. Chapter 2 will detail how D N S work and discuss what domain name space is. There are two most basic concepts in the domain name service: domain name registration and resolution. These two concepts are very important to understand D N s names and D n s servers. However, let us first briefly introduce the object of registration and parsing: host name and I p address. 1.1.1 The host name and the IP address D N S store the host name and the I P address matching with it. In a sense, the domain name system is similar to a telephone number service system that stores a username and a phone number that matches this. Although there are some other information in DNS records, there are some other information, and the DNS system itself also has some more complicated issues to be discussed, but the most important value for DNS is the most important value for users is from it. The host name finds the matching IP address and outputs the corresponding information when needed. 1.1.2 The host name of the host name and the I P address must be registered. Register is to record hostnames and i p addresses in a list or directory. The registered method can be artificial or automatic, static or dynamic. The past D n s servers are registered by artificial methods, that is, registration of the host in the D n S list is to be entered from the keyboard from the keyboard. The recent trend is a dynamic host registration. The update is done with the D H C P server, or is done directly by the host with dynamic D N s update capabilities. D h c p is an abbreviation of Dynamic Host Configuration Protocol, that is, a dynamic host configuration protocol. 2 count the first part of understanding the domain name system
Unless dynamic D N S, D N S is registered usually artificial and static. Dynamic D N S is provided in Windows 2000. When the information of the host changes, the update of the host record is usually done by manual. Figure 1 - 1 shows the registration of several hosts in the D n S server. In the D n S server, the most important information is just the host name and I P address (see Chapter 4, see Chapter 4, in some important exceptions). Figure 1-1 Registration of the host in the D n S server Figure 1 - 1 does not indicate how the host name is registered, because the registration method is not only one. Of course, artificial registration is the most common, but there are several automatic registration methods. One of the automatic registration methods is to let D N s servers to check the W i N S server. This book will continue to be mentioned in the interaction of D n s and W i n s. The automatic registration method of the W i N S server will be introduced in Chapter 1 6. Another automatic registration method is to register the name to the D n S server with dynamic D n s capabilities through the D H C P server. That is, the D h c p server automatically assigns an I P address when the client is online. Because the method has been completely tested and has been widely supported, it is the easiest way to use various D n s servers. This method works in almost any circumstances. When the registration is completed (especially when it has been reminded), all D n s servers receive registration information of the host. Most computers are registered by artificial D N s servers. This server is generally with these computers in the same building or the same campus, or at least in the same company. In general, medium or large enterprises have their own D N S servers. At this time, the host list of the editor and modify the server will summate others - such as I N t e R N e t service provider - the change in registration host is rapid and easy. When using UNIX or Windows 2000, if there is an internal environment, it is very likely to run D N S internally. Chapter 1 domain name system briefing count 3
Host 1 Host 1 Host 2 Host 3 Host 4 Host 2 Host 3 ..., etc. ... The host name of the registered host DNS server must be registered in the D n S server, which is called the primary server. The secondary D n S server automatically obtains all the data from the primary D n S server. Administrators are very interested in this backup because it allows them to place servers with the same database in several different places. For example, a central office can have a primary D N S server, while a remote mechanism can have a local auxiliary server to accelerate the lookup of the address, or prevent D N S servers from failure due to network failure. The match of the main, secondary D n s servers makes all the servers to find registered hosts, and the client can get an answer from its recent server. If the D n S server in the local network invalidates, whether the Windows 2000 is installed, Windows 2000 or other operating system, the availability of the host is a disaster. Also, if some hosts pars the domain names through the secondary server, you can also obtain a certain load balance. 1.1.3 Host address resource records No matter how the host registration is complete, the main purpose of this registration is to record the host name and its source address that other computers can be found in a list, this record. Resource record. Resource records can have a variety of formats, and in Chapter 4, a detailed introduction will be made. Figure 1 - 2 shows host records of several computers displayed on the Windows 2000 DNS manager. Figure 1-2 View Host Address Record If you are using a UNIX DNS server and text-mode profile, its entry is very like registrations in these records (IN representative i NTERNET, A representative address a ddress): If you are using Yes Windows 2000 DNS, you can record the record information in the same file, but you can also do this. The first list is a host name (such as H O S T 1), the second list is a type recorded (I n n e R n e t in this example), and the third list is the type of resource record (A representative address), and the fourth list is an I P address. Host1 in A 207.33.46.51HOST2 IN A 207.33.46.52HOST3 IN A 207.33.46.53HOST4 IN A 207.33.46.541.1.4 Analysis of the host name As long as the registration is registered, the host name can be parsed. Analysis is a client process that is the purpose of finding the registered hostname or server name to get the corresponding I P address. Once the client gets the I P address of the target host, you can communicate directly on the local online, or communicate remotely through one or several routers. Obviously, a D n S server can have many registered hosts. Analysis Register 4 of its 4 counting on the same D N S server understands domain name system
His hostname should be relatively fast. A company with thousands of hosts only require a few D n s servers. Figure 1 - 3 shows how the D n s client resolves another host name registered with the same D N S server. Figure 1-3 A D n S client query D N S server to resolve another hostname 1. The resolution of the resolver in this chapter seems to mean that the D n s server acts as all hostname parsing work. In this regard, it must be clarified. In fact, the main role is a program called a parser, and the parser runs on all computers with D n s capabilities using the T C P / I P protocol. The parser converts the path description containing the network host domain name into a query request. The parser can even cache the positioned host to accelerate the process. The parser is almost ignorant, can be local or remote, can be on the D n S server on the client. D N S servers can query another D n S server through the parser when needed, which occurs frequently. When a D n S client is used as a client, its parser is in a working state. When a D n S server acts as a client, its parser is also in a working state. When a D n S server is used as a server, its role is to respond to the query of the parser of the client, and this client may also be another D n S server. RF CDB International Standardization Agency and Volunteer Management Agency Tong Management I N T E R N E T. These regulations use R F C files through the Working Committee to assess some new ideas that may become standard. The R f C file can be proposed by a person, or it can be considered for a certain business interest. There are many R f C files to become formal standards. To view the R f C file, you can access the domain name service resource directory by H T T P: / / / / / / / / / / / / / / / / / / / / / DOMAIN, the D N S R D D DCD (Domain Name Services Resource Dictionary). For D n s, I n t e R n e t in Chapter 1 domain name system
Host 1 Answer: Query: The address of the host 3? Host 2 Host 3 Communication Start DNS Server Register Host ... Wait ... Host 1 Host 2 Host 3 Host 4 and i NTERNET itself Standards Effective Organizations are: • Internet Architecture Group (IAB, Internet Architecture Board. • Internet Authorization Address Assignment Group (IANA, Internet Assigned Number Authority, W W W. I a N a. O RG. • Internet Engineering Guidance Group (I E S G, Internet Engineering Steering Group, W W W. I E T f. O RG / I E S g. H t ml. • Internet Engineering Task Group (I E T f, Internet Engineering Task Force), W W W. I E T f. O RG. • Internet Association (ISOC, Internet Society), W W W. I S O c. O RG. • Internet Network Information Center (I N T E R N I C), W W W. I N T E R N I C. N e t. RFC 1034 "Domain Name: Concept and Device" pointed out that the parser is at least to access a domain name server to directly get the required information, or to continue tracking queries through other domain name servers. In the 5th, 6 pages of RFC 1034, "" From the perspective of the parser, the domain name system is composed of unknown domain name servers, each domain name server has one or several branches of the entire domain tree. "After the query, the result of returning to the parser may be one of the following results (see RFC 1034 (page 2 9): • One or several resource records for the required data. In this case, the parser will return to the answer in an appropriate format. • Host name error. This error is given when the name of the query does not exist. For example, it may be that the user is in an error when typing the host name. • Data is not found. This error occurs when the corresponding data is not found. 2. Reverse finding so far, our discussion is to find the I P address from the host name from the host name around D N s. However, you can also find the host name by the IP address, because the data files in the DNS server are automatic sorting or auto-index, so that quickly by the name, the reverse lookup from the IP address also requires the database to sort or index by the IP address. . Reverse lookup is also called reverse query. The D n S server is used to perform reverse lookup databases called I n - a d r. ARPA zone or the I n t e R n e t address area called the A R PA domain. If you carefully observe Figure 1 - 2, you can see 46.33.207. 46.33.207. In-Addr. A R P A region belonging to 2,0 7. This I n - a d r zone contains a database from the I P address to the hostname so that the server performs from the I P address rather than the search from the host name. Chapter 4 will discuss how this reverse mapping is established when describing the reverse address record (P R). The use of reverse lookup is not as common as it is looking for it, but it will be used from time to time. Most reverse lookups are the I P address of the local host (such as the system administrator), but it is necessary to find its host name. One of the actual use of reverse lookup is to find a whole domain name of the host known I P address. The F t p server sometimes confirms whether the connected host is the host it announced.
In addition, some tools such as N S L O O K u p also use reverse lookup characteristics (see Chapter 1 2). This technique provides another way to verify whether the connected host is a counterfeit, which can be reduced but cannot eliminate attacks. 3. The search order of the DNS server can set the D n S client to search the D n s server in the sequence of the host name. Figure 1 - 4 shows the order in which the Windows 95 client search D n s servers is displayed. The first D n S server address in the list is 1 9 2. 1 6 8. 1. 2 4, this client is registered in this server and becomes a member of the E x a m p L e. N e T domain. If the client cannot get the answer by querying the first server, it will continue to query the second and third servers. Windows 2000 client settings Allow a list of more servers in the list. Chapter 1 4 will detail the configuration of different versions of the client. 6 Message Part 1 Understanding Domain Name System Figure 1-4 DNS Server Searching Oriented DNS Server Registered by Optional Client should be the primary server of the domain, most administrators also set this server to the client's preferred Search server. But there is no reason to make a preferences that the preferred search server must be a primary server or registration server. In fact, the client uses auxiliary server as the preferred search server is quite common. When using dynamic D n s registration, if the client tries to register for auxiliary D N S server, the secondary D n S server will submit the request to the primary D N S server, which means that it will not cause real errors. Subsequent sections will introduce many strategies for different types of servers on different types of requirements. The order of search servers is completely optional. In order to solve the domain name, the first query D n S server is not necessarily the server registered by the machine. The second and third search servers can also be any server you feel suitable, such as servers in other domains, I S P's domain name servers or other servers that can quickly respond to queries. As long as one server in the list responds to the client, the search is terminated immediately. 1.1.5 The distribution of the host name is not a separate D n S server contains the host name of the world, which is impossible. If there is such a primary D n S server, the distance from the client and the server is too far away. It is also difficult to imagine that a D n S server for the entire I N t e R N e t requires much power and bandwidth. In addition, if this primary D n S server is stopped, I N t e R n e t around the world will fall into paralysis! In contrast to this idea, the host name is distributed among many D n s servers. The distribution of the host name solves the problem that is not only one D N S server, but this has another problem on the client: How do the client know which D N S server query? The domain name system solves this problem by using the top-down domain name tree, each host is the leaves of a branch in the tree, while each branch has a domain name. What is important is that every host you have is associated with a domain. How many D n s servers do you need? Although the actual number is unknown and varies depending on the reasons, it is theoretically, each branch of the domain tree needs a D n S server. Chapter 1 domain name system briefing counting 7
When a client requires another host's I P address, it is usually queried to query your own D n S server, provided that this server is listed in the search order. If this server does not have a record of the host, the query will move upward in the tree, reach the high-level server, and finally find a server that gives the results of the query. In order to fully understand this interdependence of D n s domain and server, imaging that domain name tree itself is a hierarchical domain structure, as shown in Figure 1 - 5. Figure 1-5 Distribution of DNS Servers in Domain Trees This unless otherwise reasons, the DNS server and the outside world are not connected, otherwise, each DNS server always has a member of the entire i NTERNET domain level with other servers. There is no DNS server will be an isolated island. Each server assumes a certain responsibility in the I n t e R n e T domain name service, even if it is just a small business domain name or a part of a large enterprise domain name. 1.1.6 Dedicated D N S Server D N S Servers also operate in a private network that is not connected to I N T E R N e t. These servers can even be physically connected to i n t e R n e t, but do not participate in public domain spaces. A dedicated server must be isolated from the public network, otherwise it will cause serious conflicts. The I P address must be unified allocated (see Chapter 6), and the domain name must be registered (see Appendix D). To establish a private network, the dedicated network must be isolated from the public network and only the I P address reserved for a private network. A series of issues will be encountered if common and unassigned I P addresses are used. The RFC 1597's "Dedicated I N TE E R N E TEmminal Distribution" discusses this problem. Similar to public networks, private networks also require root domain name servers. Appendix B will explain how to get information. RFC 2010 "root domain name server operating 8 counting first part of understanding domain name system
Sub-ADNS Server Domain-ADNS Server Subdomain - ADNS Server Subdomain - BDNS Server Subdomain - CDNS Server Domain - BDNS Server Domain - CDNS Server Domain - DDNS Server Domain - The Server for public root domain servers Discussion. RFC 1034's "Domain Name: Concepts and Equipment" discusses the design of the root domain server. The root domain name server is a server located at the top of the DNS domain space. 1.2 The character name of the host name is based on the requirements of the Internet RFC, the domain hostname (eg The host name given to UNIX computers can have up to 2 characters. Note that Wi NDOWS computers can have two computer names, a Windows network (N et Bios) name and a DNS name. Figure 1 - 4 Windows 95 Computer Name cannot be entered here, but in the "I Dentity" dialog box, its length cannot exceed 1 5 characters. Thewi NDOWS computer name is short and simple, such as: H Oston EWI NDOWS computer Name can be longer and more complicated, but if you use the following name: Host1- 012S- 3T4N5A6M7E8-1HOST2-2 - 023S- 4T5N6A7M8E9-2HOST3- 037S- 8T9N0A1M2E3 - 3 in the "I Dentity" dialog box name space It is considered illegal. The best way to avoid this is to choose a computer name that can simultaneously meet the DNS domain space and N et bios name space. This means that the selected computer name must not be too long, only 1 5 Characters or less, and the characters used should be legitimate in both environments. If you use the name of more than 1 5 characters, Windows 2000 ignores excess characters. For the server or other frequently used hosts, you should choose Compare the names of memories. It is best to be just a name that has a sense of meaning. Before implementing DNS, you can name it according to the intuitive naming convention. For example, Tr En Tc Arter is named Tcarte R - PC, name HKNIEF - WS, and more, the server can also be named in the servers, you can first set a range, then select the name. This can be easily included in all hosts. Contact. For vessels, you can choose Ti Tanic, e NTERPRI S e, M a y f L o W E R, for the city, optional P a R I S (Paris), M u N i c h (Munich), S E A T L E (Seattle), etc. Once a new site is established, it is very happy when they see all printers being named Vo l C a n o e s. This is good for a small business, but when it gradually increases, still wants to do this, the subdomain must be developed (and when it is more, it must be encrypted for the user. Standard naming practice). I N t e R n e T network information center I n t e R n i c, or called N i c, is a mechanism for managing domain names. Chapter 1 4 will explain how to register a new domain name to N i c. 1.2.1 IP Host Name I N t e R N e t is defined in some rules on how to select the host name. If you do not follow these rules, you may have problems when other users or application is intended to access your computer. The approved RFC 952 defines the standard of the effective hostname, that is, what kind of host names are valid and legal. RFC 1035 "Domain Implementation and Specification" must also follow.
The following is a hostname naming guide from RFC 952: • The host name is a string that does not exceed 2 characters in length, the characters used can be letters (A ~ Z), digital Chapter 1 domain name system introduction counting 9 ( 0 ~ 9), minus sign (-), point number (.). The point number can only be used to do a separator of the host name in the domain format. • There is no blank or space in the host name. • Do not distinguish between large, lowercase letters. • The first hind must be a letter. • The last character cannot be minus or point. • You cannot use a single-character host name or nickname the host name. Some hostnames have not followed these standards, such as 3 C O m. C O M, this hostname clearly violates the first character that cannot be a number of numbers. Although there is a phenomenon in which R f C standards and some actual host names, users should also be named according to standards as much as possible. The domain name follows the following rules. 1.2.2 RFC 1035: Host Name Recommendation RFC 1035's "Domain Implementation and Format" is recommended to provide a syntax for a domain name, which is especially useful for users familiar with a formal computer language format. The following is the content taken from page 6,7 from this file: 2.3 The designation domain name system has agreed to some basic issues. System implementation If you do not fully comply with these agreements in their systems, you must pay attention to these conventions that have no impact on other host access. 2.3.1 The proposed domain name syntax constitutes the D n s description of the domain name should be as generally as possible, and the basic idea is that the change in the name of the existing object is indicated as small as possible. When assigning a domain name for an existing object, the savvy user should select a name that meets some of the rules related to the domain name system standard and complies with the object, which can be published, or the conventional. For example, when naming for a mail domain, the user should follow the rules in this document, and should follow the rules in RFC 822. RFC 822 is a file related to mail. When creating a new host name, the old provisions in H O S T X T should also be observed to prevent problems when using domain names from the original software. The following syntax allows many applications (such as email, remote login) to work.
The URL containing all Internet RFC files is: H t t p: / / / / / / / w w. Isi.edu/rfc- editor / and w w w. M E R S E y w o R l D. C O m / t e c h w A T C H / S T a n D A r D S10 counting first part of understanding domain name system
1.2.3 Wi N D O W S (N e T B I O S) Computer Name Wi N D O W S Computer Name The length must be less than or equal to 1 5 characters to meet the requirements of N e T B I O S on the name length. Non-case case in the name, name H o S T - O N E, H O S T-O N E, and H O S T - O N E are equivalent to U N i x computer and Wi N D O W s computer are equivalent. However, the Wi N D O W S computer name cannot contain unauthorized characters in D N s. If the computer name contains this illegal character, there is a problem when registering in D N s, regardless of this registration is manually registered. Wi N D O W S should only use legal D n s characters to avoid errors. The following names are legal in WINS, but for most DNS servers is illegal: 1 is a number (start) Under _ score (Underline is not allowed) Space ghost (not allowed space bar) This is very Good suggestions, that is, only legal DNS names for Wi NDOWS computers. Two different names tables may need to be retained when transplantation and upgrade, but it should be tried to avoid this. 1.3 The host name is incomplete in the domain of the computer, and this host name is incomplete. Of course, if you use the computer and search host in the same domain, the parser may add a domain name based on the above assumption. However, if the searched host is in another domain, and D N s did not find it, it is likely that the client uses unqualified domain names, which means information that does not contain domain members. Many operating systems provide users with a method of "conjecture-add" process. The whole domain name (F q D n, full Qualified Domain Name) refers to the host name plus a full path, and all domain members in the sequence are listed in the full path. The whole domain name can logically indicate where the host is, and it can be said that the whole domain name is a completely representation of the host name. The information contained in the whole domain can see the position in the domain name tree. For example, the whole domain of the WE B servers of C M E C O m P A N y can be W W W. A c M E C O m P A N y. C O m, and if the W W host is in the sales unit, its full domain name can be W W W. S A L e s. A c m e c o m p a n y.com. When the name given like A c m e c o m p A n y is not A c m, when they often refer to the host name, and the name is a whole domain name. This difference is very important when understanding and controlling the parsing process. The period actually points out the root of the domain tree. The whole domain name is very useful in practice. Email uses the whole domain name as the email address of the recipient, such as JaniceJones @ Acmecompan Y. CoM, where the recipient is JANICEJONES, followed by the recipient name is the symbol @, @ is the whole country name of the mail server, or is The mail server is in the domain name of the company, and finally the top-level domain name. COM. C O m means A C M E C O M P A N Y is a commercial institution. 1.4 Selecting a domain name Select a domain name is a very complex work. As I N t e R N e t is rapidly spread in recent years, some people have discovered that speculation on domain names can bring huge profits.
In other words, a person registers many domain names for themselves, I hope that another person who is not very lucky is ready to open a company, and try to register an identical domain name if this domain name has been registered, then the latter must choose another Domain name, or try to advise the former to abandon this domain, and the latter will be profitable for the former. When you are ready to register a domain name, take a few good names, it is best to imply your expected use. And consider what top domain names for use. . C O m is used for commercial purposes. N e T is usually used for I S P and other networked institutions, and O RG refers to non-profit or social organization. Relatively speaking, these are not very strict. For the Top-Top Field Chapter 1 domain name system introduction, there are 11 uses, many entities have many opportunities to use similar names, but they can still distinguish between their respective intentions and purposes. E d u is used for education, G O V and. M i L are used for government and military, which are constrained according to their respective possible registration. Additional top-level domain names, such as. L A W, I n c ,. m A I l ,. g A m e s ,. l e a r n, provides more options - assuming that speculators do not use them. The use of the word head is also a good way to provide a domain name. Remember, the shorter the domain name, the greater the possibility of being registered by others. Many times, registering a domain is like trying to apply for a personal license brand. People who want to make some unique insights must think about open and a bit of creativity. When you are ready to register a domain name, i N T E R N i c provides a lot of effective tools to help find a unique name and register. For information about INTERNIC, query w w w. I n t e R n i c. N e t, if you are interested, it is possible to find some new top-level domain names. There is a lot of listings that cannot be listed here, but it can easily find available information on i n t e R n e t. 1.5 Summary This chapter mainly introduces the basic concepts of D N S and some host naming rules. The following chapters will discuss how to establish and manage D N s servers in depth. Each computer on I P Address I N t e R n e t has an I P address, one I P address is four numbers on a row, each number from 0 to 2 5 5, separated by a dot number. For example, 1 2 3. 2 1. 9. 1 and 1 0. 1. 1. 3, a single I P address can automatically allocate. In many cases, D N s does not care about their allocation. A new standard called IPv 6 may be implemented. More information can be obtained in the chapter after this book. 12 counting the first part of understanding the domain name system
