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I am slightly confused between DNS and Name server. Are they the same thing or is there a difference between two?

5 Answers 5

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There is no such thing as a Domain Name Server.

DNS stands for Domain Name System, which is simply a hierarchy of Name Servers that has the intent to translate host names into IP addresses on a global scale. A name server hosts or caches these translations, in the case where they are hosted the name server is often called a DNS Server.

Counting all name servers is a bit tricky, because you can't simply enumerate all the domains.

Let me give you an example on resolving superuser.com in a non-cached way:

  • The name server that I use is 192.168.1.1.

    This is my local router which caches DNS entries, it has a Hosts file to reroute malicious domains.

  • The router has the name servers 8.8.4.4 and 8.8.8.8 set, known as Google DNS, they also cache.

  • Google DNS will contact authoritative root name servers, which are the top of the DNS hierarchy.

  • Google DNS will contact the .com name servers, the IP of which it received from the ARNs.

  • Google DNS will contact the DNS server for superuser.com, of which IP it received from .com.

    A simply whois reveals:

    NS1.SERVERFAULT.COM
    NS2.SERVERFAULT.COM
    NS3.SERVERFAULT.COM
    

    The IPs for these name servers are known as they are registered at the .com name server, when you register a new domain you always have to fill in the DNS servers that you use along their IP.

  • Google DNS will contact the DNS servers of superuser.com to find the IP of superuser.com:

    nslookup superuser.com NS1.SERVERFAULT.COM
    Server:  NS1.SERVERFAULT.COM
    Address:  64.34.119.33
    
    Name:    superuser.com
    Address:  64.34.119.12
    

I would suggest you to read through Domain Name System and Name Servers for more details.

The term name servers are also used in different contexts, read Spiff's answer for more.

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    Side fact: . is the root domain, example: google.com. Note the extra dot in the URL. :) Aug 7, 2011 at 9:54
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    @Tom: Thanks for that great explanation. I am pretty new to the networking side of IT. But I thought, some where a record must be maintained about the count of TLD and the list of nameservers and the webaddress registered under them.
    – Kunal
    Aug 8, 2011 at 1:30
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    @Kunal: Maybe, I'm just unaware of it and it seems hard to find so I think such count does not exist... Aug 8, 2011 at 12:14
  • According to Wikipedia name server is a more broad term compared to DNS server: "A name server is a computer application that implements a network service for providing responses to queries against a directory service." And DNS is an implementation of such a service. And the very page you mentioned in your response contains the word "DNS server." At least at the moment.
    – x-yuri
    Apr 2, 2019 at 13:46
  • when an nslookup for google.com is done, i get different results with different name servers. How is this possible - in any case, with caching or hitting the authoritative name server directly, i would expect the same IP every time.
    – samshers
    Aug 29, 2019 at 13:59
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Tricky!

A DNS Server typically is for converting FQDN (www.xxx.com) to IP Addresses (192.168.0.1).

(A DNS Server also does a lot more, it can perform reverse lookups, and in recent years does a lot of other tasks with text tags, geo-ip and a lot more).

On the other hand, "Name Server" is typically used to locate a DNS Server.

For example, On a Whois record, a Name Server is typically the address for the DNS server that hosts the records for that domain.

A further more complicated example is, if you queried www.superuser.com, you would go to your dns server and a recursive DNS lookup would occur on the superuser's nameserver.

As for how many are there - how long is a piece of string! This is an impossible question to answer... As a guess, I would put it in to the hundreds of thousands, if not low millions (for publicly accessible DNS Servers).

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    There are 13 names for the root nameservers, but they exist in more than 13 physical locations.
    – soandos
    Aug 7, 2011 at 8:36
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In some contexts, the term "name server" can refer to servers that aren't part of the Internet Domain Name System. For example, a WINS server is a name server for Microsoft's legacy proprietary networking protocols. There may have been other legacy LAN systems that had their own types of name servers that weren't part of Internet DNS.

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  • +1 for mentioning what I immediately thought of when I read the question. Unfortunately, then -1 again for gross abuse of the word "legacy".
    – JdeBP
    Aug 8, 2011 at 0:24
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    @JdeBP I think you misread me. My use of "legacy" has no value judgment, so it's not a pejorative. I mean it simply in the sense of legacy systems: Something left over but still in use from a previous generation of technology. English is an ever-changing language and this usage of "legacy" has been in common use in the IT industry for several decades now. I agree with your page that it's sometimes misused as a pejorative, but there are also valid uses of it in IT discussions.
    – Spiff
    Aug 8, 2011 at 0:48
  • No it hasn't been in use for several decades. It's a fairly recent abuse, not going back far beyond 1999, and an abuse it is. It is just as much an abuse when abused in the phrase "legacy system" as elsewhere. One of these days I'm going to record the ludicrous situation of the company that employed this egregious abuse of the language for sales purposes only to end up with two different "legacy" modes in its publications with no clear distinction between the twain.
    – JdeBP
    Aug 8, 2011 at 1:02
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    @JdeBP I recall IT magazines in the very early 90's, as the burgeoning of PC LANs had ushered in the "client-server" era, referring to minicomputers and mainframes as "legacy systems". I'll bet I can find citations from the early 80's as well.
    – Spiff
    Aug 8, 2011 at 1:08
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    In the context above, the word "legacy" was clearly not used as a pejorative. It's clear the tone was informative and not opinionated.
    – surfasb
    Aug 8, 2011 at 1:23
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The acronym DNS means Domain Name System. It is a distributed system for translating host names (and other data) to IP addresses in a large scale (world). The name server is usually what people call the local DNS server that a workstation/PC can use as its entry point into the DNS. It will resolve local names, but delegates to other names servers for those it can't answer.

There are many name servers, but you don't need to know how many since they are queried as needed. There are only a few "root" name servers (the DNS is hierarchical).

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DNS is Domain Name System and there is nothing like Domain Name Server!

The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. Most prominently, it translates easily memorized domain names to the numerical IP addresses needed for the purpose of locating computer services and devices worldwide.

A DNS has a lot of DNS record types like

  1. A : Returns a 32-bit IPv4 address, most commonly used to map hostnames to an IP address of the host
  2. AAAA : Returns a 128-bit IPv6 address, most commonly used to map hostnames to an IP address of the host.
  3. MX : Maps a domain name to a list of message transfer agents for that domain and many more... One of them is also
  4. NS(Name Server) : Delegates a DNS zone to use the given authoritative name servers

Note : As of February 2013, there are 13 root name servers specified, with names in the form letter.root-servers.net, where letter ranges from A to M(though they exist in more than 13 physical locations). Here is the list.

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