dns questionaire
Authoritative DNS server
Put simply, an authoritative DNS server is a server that actually holds, and is responsible for, DNS resource records. This is the server at the bottom of the DNS lookup chain that will respond with the queried resource record, ultimately allowing the web browser making the request to reach the IP address needed to access a website or other web resources. An authoritative nameserver can satisfy queries from its own data without needing to query another source, as it is the final source of truth for certain DNS records.
what are the types of dns queries
recursive query In a recursive query, a DNS client requires that a DNS server (typically a DNS recursive resolver) will respond to the client with either the requested resource record or an error message if the resolver can't find the record. iterative query in this situation the DNS client will allow a DNS server to return the best answer it can. If the queried DNS server does not have a match for the query name, it will return a referral to a DNS server authoritative for a lower level of the domain namespace. The DNS client will then make a query to the referral address. This process continues with additional DNS servers down the query chain until either an error or timeout occurs. non-recursive query in this situation the DNS client will allow a DNS server to return the best answer it can. If the queried DNS server does not have a match for the query name, it will return a referral to a DNS server authoritative for a lower level of the domain namespace. The DNS client will then make a query to the referral address. This process continues with additional DNS servers down the query chain until either an error or timeout occurs.
recursive dns resolver
the recursive resolver is the computer that responds to a recursive request from a client and takes the time to track down the dns record. it does this by making a series of requests until it reaches the authoritative dns nameserver for the requested record.
eight steps in a dns lookup
1.a user types 'example.com' into a web browser and the query travels into the internet and is received by a dns recursive resolver. 2.the resolver then makes request to the .com TLD. 3.the tld server then responds with the ip address of the domains nameserver, example.com. 4.lastly, the recursive resolver sends a query to the domains nameserver. 5.the ip address for example.com is then returned to the resolver from the nameserver. 6.the dns resolver then responds to the web browser with the ip address of the domain requested initially. 7.the browser makes a http request to the ip address. 8.the server at that ip returns the webpage to be rendered in the browser.
what are the four dns servers involved in loading a webpage
DNS recursor - is designed to receive queries from client computer. root nameserver - the root server is the first step in translating(resolving) human readable host names to ip addresses. TLD nameserver - top level domain nameserver is the next step in the search for a specific IP address, and it hosts the last portion of a hostname Authoritative nameserver - is like a dictionary on a rack of books, in which a specific name can be translated
dns records
IPv4 SOA NS A MX TXT CNAME
what is a dns resolver?
The DNS resolver is the first stop in the DNS lookup, and it is responsible for dealing with the client that made the initial request. The resolver starts the sequence of queries that ultimately leads to a URL being translated into the necessary IP address. It's important to differentiate between a recursive DNS query and a recursive DNS resolver. The query refers to the request made to a DNS resolver requiring the resolution of the query. A DNS recursive resolver is the computer that accepts a recursive query and processes the response by making the necessary requests.
what is dns caching?
caching is to temporarily stored data in a location that results in improvements in performance and reliability for data requests. dns caching involves storing data closer to the requesting client.
Top level domains examples
com net org us edu au
dns resolver
dealing with the client that made the initial request. the resolver starts the sequence of queries that ultimately leads to a url being translated into the necessary ip address.
Second level domain examples
gfotechnologies nwcrane nwlogistics google microsoft
third level domain examples
internal dmz learning hosting
how to reset dns resolver cache
ipconfig /flushdns
how to flush dns
ipconfig /flushdns pconfig /registerdns ipconfig /release ipconfig /renew netsh winsock reset