Updating zone files on primary dns
To solve this dilemma, a system was developed whereby people can use "friendly" names that are then translated automatically into IP addresses that computers use to locate each other and to communicate. Before the advent of DNS, HOSTS files were used for name resolution, but as the Internet quickly grew in size and popularity, HOSTS files became impossible to maintain and keep current.
When the Internet community realized there was a need for a more manageable, scalable, and efficient name-resolution system, DNS was created.
Master Server will resolve the names for every hosts which we defined in the zone database and use UDP protocol, because UDP protocols never use the acknowledgement process while tcp uses acknowledgement.
DNS servers also use UDP protocols to resolve the query request at the earliest. (dot) at the end of the say to search the root server of namespace.
Zone transfers between the primary and secondary name servers will occur over TCP port 53. Zone files can be modified on the primary name servers.Having a thorough understanding of the topics presented here is important to both the exam and on-the-job success.Each machine on a computer network is assigned a unique network address.If they don’t have info about such requested query they will pass the request to the Top Level domain (TLD), if TLD say I don’t know the request, may be the authoritative server know your request, it will forward to authoritative servers, here only defined as address .56.In mean time authoritative server will give the answer to TLD and TLD will pass to root server and root will provide the info to browser, hence the browser will cache the DNS request for future use.