what is a domain server?

[jes]

topic says it all.

[Ghost_Hacker]

In Windows networking a Domain server (or Domain Controller) is a server that takes care of authentication or access task for a network. A Domain server defines the resource "area" that users have access to.


Domain servers are not the same as Domain Name servers (or DNS).


Domain Name Servers hold IP address to host name and host name to IP address mappings. For each domain there is usually a primary and secondary Domain Name Server.


If a DNS server does not host the actual mappings it might forward a request to a higher level DNS server which holds the information that will point to the requested domain's primary DNS server. (if it doesn't already have that information.)

[rahulkothari]

GH: Domain servers are not the same as Domain Name servers (or DNS).

Hey GH, thx for informing. I was "pretty sure" that Domain Servers and Domain Name Servers are same. (i even visited howstuffworks.com and was about to post the reply "how dns servers work")

[jes]

Domain servers in listed order:

CROCODILE.EBAY.COM 216.32.120.21
NS.EXODUS.NET 206.79.230.10
NS2.EXODUS.NET 207.82.198.150
NS1.BEST.COM 128.121.101.11
PACIFIER.COM 199.2.117.66


this is what i mean, this is ebay. does this mean than ebay is on windows computers?

[Ghost_Hacker]

Those are Domain Name servers (DNS) not Domain servers.




Domain Name: EBAY.COM
Registrar: NETWORK SOLUTIONS, INC.
Whois Server: whois.networksolutions.com
Referral URL: http://www.networksolutions.com
Name Server: CROCODILE.EBAY.COM
Name Server: NS.EXODUS.NET
Name Server: NS1.BEST.COM
Name Server: PACIFIER.COM
Name Server: NS2.EXODUS.NET
Updated Date: 12-jun-2002

[jes]

Then, what is that?

[Ghost_Hacker]

OK, you may be confused so let me throw some knowledge your way. :)

Take a look at this snipit from RFC 882 (RFC882 and RFC883 define the DNS system)


"
The DOMAIN NAME SPACE, which is a specification for a tree
structured name space. Conceptually, each node and leaf of the
domain name space tree names a set of information, and query
operations are attempts to extract specific types of
information from a particular set. A query names the domain
name of interest and describes the type of resource information
that is desired. For example, the ARPA Internet uses some of
its domain names to identify hosts; queries for address
resources return ARPA Internet host addresses. However, to
preserve the generality of the domain mechanism, domain names
are not required to have a one-to-one correspondence with host
names, host addresses, or any other type of information.

NAME SERVERS are server programs which hold information about
the domain tree's structure and set information. A name server
may cache structure or set information about any part of the
domain tree, but in general a particular name server has
complete information about a subset of the domain space, and
pointers to other name servers that can be used to lead to
information from any part of the domain tree. Name servers
know the parts of the domain tree for which they have complete
information; these parts are called ZONEs; a name server is an
AUTHORITY for these parts of the name space.

RESOLVERS are programs that extract information from name
servers in response to user requests. Resolvers must be able
to access at least one name server and use that name server's
information to answer a query directly, or pursue the query
using referrals to other name servers. A resolver will
typically be a system routine that is directly accessible to
user programs; hence no protocol is necessary between the
resolver and the user program.



Notice that nowhere is a DNS server refered to as a "domain server" the correct short form is "name server".


I belive the short form "domain server", as listed in your whois query result, is a hold over from the days when Unix ruled the net. (back then all computers, be they servers or workstations, where called "host".)


Then, what is that?


Refer to my first post or look at the "name server" info above.


Hope this helps :)

[jes]

So the name servers are just basicly routers, except they are software and not hardware?

[Ghost_Hacker]

No, they're not routers, they don't route traffic.
What they do is hold databases which contain list of host names and their IP address.

When you type www.pcguide.com into you browser, it must convert the name into a IP address before it can "talk" to a remote computer. To do this it "contacts" the DNS server in your IP properties and ask for the IP address of www.pcguide.com. In most cases the DNS server listed in your IP properties will have no clue what IP address is used by www.pcguide.com. So that DNS server will ask a another higher level DNS server for the authoritative DNS server for the pcguide.com domain. ( This might be a whole set of queries that walk the domain space "tree". Starting at the root "." and preceding down thur ".com" to"pcguide.com".) At some point the authoritative server for the pcgude.com domain will have a listing for the host name "www" and will return that IP address to your "browser" which can now talk to www.pcguide.com.

[jes]

CROCODILE.EBAY.COM 216.32.120.21
NS.EXODUS.NET 206.79.230.10
NS2.EXODUS.NET 207.82.198.150
NS1.BEST.COM 128.121.101.11
PACIFIER.COM 199.2.117.66

So those are just a list of computers that know the IP address of ebay.com?

[Ghost_Hacker]

You got it. :D