Know How DNS Works

Domain Name Server (DNS) is important but invisible part of the Internet, and is one of the largest databases on it. Each computer on the Internet is assigned a unique address, called IP address, which is 32 bits and is expressed as 4 octets. The method used to represent these IP addresses is known as the comma. A typical address looks like: 199.249.150.4 It is very difficult to take the IP addresses of all the sites you visit every day, because it is not easy to remember strings of numbers. But we remember the words. This is just the domain names in the image. To connect to a specific area, you must know your IP address, but you do not need to know its URL. DNS benefits of IP addresses and names. Names and numbers DNS converts the machine (for example www.xyz.com) into IP addresses (for example, 199.249.150.9). Basically, this means a name and address of an address to a name. The investigation of the IP address of the computer name is called reverse mapping. Http: / / www.xyz.com When you type in your browser, your browser must first obtain the IP address www. xyz.com. The machine uses a directory service to search for IP addresses, and the DNS service is called. When you type machines www.xyz.com first contacts a DNS server asking it to find the IP address of www.xyz. no. This DNS server may contact other DNS servers on the Internet. DNS, and therefore considered the worldwide network of servers. The great advantage of DNS is that no organization is responsible for the upgrade. This is called a distributed database. The three-letter codes for a DNS server is simply a computer that is running the DNS software. The most popular is the software DNS BIND (Berkeley Internet Name Domain) DNS is hierarchical, tree-structured system. The top is given by ..'' and is known as the root system. Under the root there are seven sub-domain nodes and immediately no , org , gov , ten kilometers , net , edu ',' int ' , Etc. DNS consists of two components <li>; <li> Solve Name Name: This makes the task of finding the names. Generally, it is a name for a group of machines. If the name does not contain the information requested, which will be in contact with a different name. But it is not necessary for each server to know how to contact another server. All names to know how to contact the following names, and again, you know the location of each server names for all second level domains. Correction: It is running on a client computer to initiate DNS lookup. It contains a list of names to use. As we read, what role each of these names is to resolve name queries. There are three types of names in the name of the primary, secondary name, and caching. The secondary name servers are configured for backup purposes. The cache name only to resolve complaints, but did not file DNS database. It is important to note here that any name change to primary education should be propagated secondary name. This is because the primary records of names from the database. The changes are spread over an area of transfer. How caching DNS work using the principle of Cache for its operation. When we receive information about a name mapping, which stores information. New questions for the same mapping will use this cached result, thereby reducing costs for research. The names of cache, not always. Caching is an element known as Time To Live (TTL) and TTL determines how long a cache server for a piece of information. So when hide name servers receive an IP address, which receives TTL with it. Caches of names from the IP address of the time period after disposal. When a process to determine the needs of an IP address to the DNS address, which calls on the local machine to resolve the address. This can be done in different ways: the search box. UNIX machines, the table is / etc / hosts. The process communicates with a local name. This is the name of a UNIX system. By sending a massage to the remote system that is identified from information in the file / etc / resolve.conf. When it receives a request to name an area that does not work, you can return a reference to the customer, giving the names better. In general, operating in the mode where one Recursive DNS server application can not handle a higher level of the server, and so on, the application can be processed, or at the root of the DNS name space is reached. The names of links to other names by which you can go through the entire hierarchy of domain names. A number of names from the address must be configured. After that, it is able to use the protocols for the DNS to find the name of any manager or hierarchy of DNS names. So when a name to receive an application, you can do the following options: You can answer the request with an IP address. This method is called iterative. In this sense, the client simply asks the server to resolve a domain name. Server to access the database, you can find your IP address and return address. If the server can not find the address, which returns an error; DNS not found ). Contact a different name, and try to find the IP address of the requested name. Returns a reference to the customer, enter the IP address of the best names. A user interface, called nslookup'is available on the UNIX system. With this you can fill a function of the DNS. This program also displays the results to the user. Using nslookup, you can get a list of all computers in a domain. To do this, you must first identify the names of the region. The threats that are associated with the DNS are due to the lack of integrity and verify the authenticity of data stored in the DNS server. In addition, other protocols can use the host name as a mechanism to control access. Internet Engineering Task Force (IETF) has DNS (DNSSEC) extensions DNS protocol. The main objective of DNSSEC is to provide authentication and integrity in the DNS. These links are provided by the use of cryptography About the author Pawan Banga,
Technical Director,
Birbal, Ebirbals, SeoBirbals, Hbirbals
India. Visit us at: http://www.birbals.com target = _New www.birbals.com, http://www.ebirbals . com target = _New www. ebirbals.com, http://www.hbirbals.com target = _New www.hbirbals.com, http://www.seobirbals.com target = _New www. seobirbals.com pawan@ebirbals.com pawan@ebirbals.com