The internet and the World Wide Web are unwarranted frontiers that rely on computer languages , code , and web browsers to see and share datum and information . One of the most fundamental instruments of the internet is the Domain Name System , orDNS . ( Although many masses think " DNS " stands for " Domain Name Server , " it really stands for " Domain Name System . " )
DNS is a communications protocol within the set of standards for how computers commute data on the internet and on many private net , known as the TCP / IP protocol suite . Its aim is vital , as it helps convert easy - to - sympathize domain gens like " howstuffworks.com " into an Internet Protocol ( IP ) address , such as 70.42.251.42 that calculator use to discover each other on the mesh . It is , in short , a system of couple name with numbers .
The DNS concept is like a headphone book for the internet . Without this kind of way finding system , you ’d have to fall back to much more complicated and esoteric mean value to sift through the virtual exposed plain and impenetrable cities of data strewn across the globular cyberspace … and you may reckon that it would n’t be intimately as much fun , especially since there are now hundreds of millions of land names [ root : VeriSign ] .
Without DNS server , the net would shut down very apace . But how does your computer know what DNS server to use ? Typically , when you connect to yourhome meshing , internet service supplier ( ISP ) or WiFi mesh , the modem or router that assigns your computer ’s web address also sends some important mesh configuration information to your reckoner or mobile gadget . That configuration includes one or more DNS servers that the gimmick should use when translating DNS names to IP address .
So far , you ’ve read about some important DNS basic . The rest of this clause plunk deeper into domain name servers and name answer . It even includes an innovation to pull off your own DNS host . have ’s bulge out by look at how IP addresses are structure and how that ’s important to the name resolution process .
DNS Servers and IP Addresses
You just learn that the main job of a land name server , or DNS server , is to resolve ( translate ) a area name into an IP destination . That sounds like a round-eyed task , and it would be , except for the following points :
vane serversand other computer that need a consistent degree of contact use inactive IP addresses . This means that the same IP address is always assigned to that system ’s mesh interface when it ’s on-line . To make certain that interface always get the same IP address , IP associate the address with the Media Access Control ( MAC ) address for that web interface . Every web user interface , both wire and wireless , has a unequaled MAC address embedded in it by the manufacturer .
Now , allow ’s look at the other side of the DNS equation : domain names .
Domain Names
If we had to remember theIP addressesof all our favorite websites , we ’d probably go nuts ! Human organism are just not that good at remembering strings of numbers . We are skillful at recall countersign , however , and that is where field names come in . You probably have hundreds of domain names stored in your head , such as :
You ’ll realize domain name as having strings of characters carve up by dots ( periods ) . The last word in a domain name represents a top - degree demesne . Thesetop - tier domainsare controlled by the IANA in what ’s shout the Root Zone Database , which we ’ll try out more tight later [ origin : IANA ] . There are more than 1,000 top - level domain of a function , and here are some of the most vulgar :
In a domain name , each word and Elvis combination you sum before a top - story knowledge base indicate a level in the domain structure . Each grade concern to a host or a group of waiter that deal that domain level . For example , " howstuffworks " in our domain name is a second - level knowledge domain off the COM top - storey domain .
An organization may have a hierarchy of sub - domains further engineer its cyberspace bearing , like " bbc.co.uk " which is the BBC ’s domain under CO , an additional degree make by the domain name authority responsible for for the U.K. land code .
The unexpended - most Holy Scripture in the domain name , such as web or mail , is a host name . It intend the name of a specific machine ( with a specific IP address ) in a land , typically dedicated to a specific purpose . A given domain can potentially control millions of server names as long as they ’re all singular to that field .
The " http " part brook for Hypertext Transfer Protocol and is the protocol by which information is sent by the user to the website she is call in . Nowadays , you ’re more likely to see " HTTP " which is a sign the information is being commit by impregnable communications protocol where the information is code . This is specially authoritative if you ’re provide a credit card number to a web site [ source : EasyNews ] .
Later , when we look at how to make a domain name , we ’ll see that part of registering a domain require name one or more name servers ( DNS servers ) that have the agency to correct the host public figure and Italian sandwich - domains in that sphere . Typically , you would do this through a host inspection and repair , which has its own DNS servers . Next , we ’ll take care at how these DNS server manage your domain , and how DNS servers across the internet work together to ensure dealings is rout the right way between IP addresses .
The Distributed System
Every domain has a domain name host handling its requests , and there is a person or IT team wield the records in that DNS host ’s database . No other database on the planet gets as many requests as DNS server , and they handle all those inquiry while also processing data updates from millions of people every day . That ’s one of the most amazing percentage of DNS — it is completely distribute throughout the worldly concern on meg of machine , manage by zillion of people , and yet it act like a single , incorporated database !
Because deal DNS seems like such a adult job , most people tend to give it to the IT professional . However , by acquire a lilliputian moment about how DNS works and how DNS server are distributed across theinternet , you could manage DNS with self-confidence . The first matter to have it away is what the role of a DNS server is on the internet where it domicile . A DNS waiter will have one of the following as its elementary task :
DNS servers that perform the first chore are unremarkably contend by your internet divine service provider ( ISP ) . As mentioned earlier , the ISP ’s DNS host is part of the meshwork configuration you get from DHCP as before long as you go online . These servers reside in your ISP ’s data centers , and they handle requests as follow :
The second category of DNS server mentioned above is typically associated with entanglement , mail service and other cyberspace orbit host service . Though some hard-core IT gurus set up and do their own DNS server , host services have made DNS direction much easy for the less technical audience .
A DNS host that negociate a specific knowledge domain is called the start of sanction ( SOA ) for that domain . Over prison term , the results from looking up hosts at the SOA will propagate to other DNS host , which in act propagate to other DNS server , and so on across the cyberspace .
This great web of DNS server includes the root name server , which come out at the top of the land power structure for a given top - level domain . There are century of solution name servers to select from for each top - level domain . Though DNS search do n’t have to start at a root name host , they can meet a root name host as a last resort to help get over down the SOA for a area .
Now that you recognise how DNS servers are interconnected to improve the name resolution process , let ’s reckon at how you may configure a DNS server to be the authority for your domain .
Creating a New Domain Name
When you desire to make a unexampled land name , you call for to do the following :
Whether your SOA is somewhere else or on your own arrangement , you could extend and alter your DNS mise en scene to add U-boat - domains , redirect e - post and control other services . This information is kept in a zone single file on the DNS host . If you ’re running your own waiter , you ’ll probably need to manually edit the zone data file in a textual matter editor in chief . Many registrars today have a web interface you could apply to care DNS for your domain . Each newfangled configuration you lend is called a record book , and the follow are the most common eccentric of records you may configure for your DNS waiter [ informant : GoDaddy.com ] .
The following is an example of what a zone Indian file might look like for those who are edit it directly in a text editor . Note that the inwardness column ( 2nd item on each line ) includes a record type from those listed above . When you see an " @ " in the left-hand column , it means that the phonograph recording lend oneself in all cases not otherwise specified :
@ NS auth-ns1.howstuffworks.com
@ north auth-ns2.howstuffworks.com
@ maxwell 10 mail
mail A 209.170.137.42
vip1 A 216.183.103.150
www CNAME vip1
Typical users will probably get the most manipulation out of MX and CNAME phonograph record . The MX records allows you to point your mail services somewhere other than your hosting party if you choose to apply something like Google Apps for your demesne . The CNAME records have you point emcee names for your land to various other locations . This could include set google.example.com to redirect to google.com , or adjust up a dedicated game server with its own information science name and address and point it to something like gameserver.example.com .
DNS is Constantly Evolving
You should understand that DNS is not a still concept . In late 2018 , ICANN finally rolled out unexampled security measures feature for DNS . In shortsighted , those change affected the cryptologic tonality used in the Domain Name System Security Extensions ( DNSSEC ) protocol , known by techies as the etymon zona fundamental signing key ( KSK ) . The certificate improvements were necessary , says ICANN , because of the means networks are rapidly changing and expand , in part due to theInternet of Things , which bestow millions of newfangled interconnected gadget into the net ’s fold [ source : Cooney ] .
Those condom measurement are fabulously significant because vicious - tending hackers often seek to tap into the DNS system to slip personal data or simply work mayhem , for example , in attacks like DNS highjacking . That means defense - disposed computer users and IT pro alike must abide up to escort on preventive criterion to forbid DNS poisoning attacks and demurrer - of - overhaul attacks , among others [ sources : Greenberg ] .
