?
Solved

Name Resolution

Posted on 2010-01-07
11
Medium Priority
?
368 Views
Last Modified: 2013-11-25
In Domain Network Environment ( Microsoft System)  :-
On command line , when we type  PING ab.xyz.local , there is a reply inclusive of IP Address .
ab.xyz.local is a Host Name ( FQDN) .

In Workgroup Environment ( Microsoft System) :-
On command line , when we type   PING computer1 , there is a reply inclusive IP Address .
"computer1" is a Computer Name .

To me , there are some protocol help to resolve the Name to IP Address on above examples .

To Resolve Host Name to IP Address , is using DNS Server . When DNS Server is  down ,and we  PING ab.xyz.local, it will fail , am I right ?

To resolve Computer Name to IP Address , I suppose it should use WINS Server .
In Workgroup environment , without WINS Server and DHCP Server present in this network ,if there are 2 XP Pro computers can PING each other with " computer name "  like  PING Computer1 .  Which protocol resolve this computer name ??  ( once we "ping computer1" , the reply inclusive IP Address , I suppose specific protocol has resolved computer name to IP addrsss ? )

What I am confused is :- without WINS SERVER present , for XP Pro systems , which protocol resolve Computer Name to IP Address ??


   
0
Comment
Question by:kcn
  • 5
  • 4
  • 2
11 Comments
 
LVL 71

Expert Comment

by:Chris Dent
ID: 26199313
> am I right ?

Yes, unless the answer for that exists in the local DNS cache (see ipconfig /displaydns).

> To resolve Computer Name to IP Address , I suppose it should use WINS Server .

Depends on what is attempting to resolve the name. If you use Ping it will use the DNS Client first, WINS after.

> Which protocol resolve this computer name ??  

NetBIOS Broadcast provides the answer, a request is sent to the network broadcast address asking who has the name. The computer with the name replies.

Chris
0
 
LVL 57

Expert Comment

by:giltjr
ID: 26199364
In addtition to querying a DNS server each computer will have a "hosts" file.  You can define DNS entries in the hosts file and normally when doing IP based name look up the computer will look in this file before it sends a request to the DNS server.  So, it is possbile to have a entry for host  ab.xyz.local in your hosts file.

You mentioned WINS, which typically means you are also running NETBIOS.  Well NETBIOS has LMHOSTS file which is the same basic thing as IP's HOST file.  In fact LMHOSTS is LanManger Hosts.  The entries in the LMHOSTS file are different from what you would put into HOSTS, as they also need to include the special codes that NETBIOS uses to identify what NETBIOS services are running.  In addtion to WINS and LMHOSTS, NETBIOS will also do a name resolution broadcast.  So it will send out a broadcast on its IP subnet saying "hey anybody named bill out there?"

So for any system, not just XP, if DNS is down, WINS is down, there is no host entry in the hosts file, and there is no entry in the LMHOSTS file, a NETBIOS broadcast will be sent out.

There are different NODE types (you will see your node type if you enter "ipconfig /all" at a comand prompt).  Which name resolution methods your computer uses, and the order it trys them, is based on the node type.
0
 

Author Comment

by:kcn
ID: 26202490
Dear Chris and giltjr ,

Correct me if I am wrong .

1) The NetBIOS Broadcast is build-in service in Microsoft OS ( including XP Pro , Server 2003 etc ? ) ?
    I thought NetBIOS is only exist on legacy OS like Win 95 and Win98 ?

2) The NetBIOS Broadcast works independent regardless WINS or LMHOST File existence ?

3) In the absent of  WINS Server ,  when I  " PING Computer1 " , there is the  reply echo  associated
    with IP  Address , in fact this IP Address is  "find out " by  NetBIOS Broascast  ?

 
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 

Author Comment

by:kcn
ID: 26202508
By the way ,

when I run " ipconfig/all" , I find out that the node is "unknown"  ==>  node type :     unknown

Please advise why it display " unknown " ??
0
 
LVL 71

Expert Comment

by:Chris Dent
ID: 26202523

1. It's still there for Legacy Support in 2003, XP, Vista, Win 7, etc), upgrades to network protocols happen very very slowly.

2. Normally LMHosts, then WINS then Broadcast, but the order can be configured using the Node Types giltjr mentioned.

3. Yep. Before ping can begin sending ICMP the name must be resolved to an IP. Only after that has happened does Ping start to do its real job.

Chris
0
 
LVL 57

Expert Comment

by:giltjr
ID: 26202621
Christ-Dent is correct in his comments.

Now, under the new operating system you can disable NETBIOS, but by it is enabled.  Another reason for NETBIOS is that there are still a lot of programs and enviroments that still depend on it.  

For example, any time you are in a Windows Workgroup environment typically NETBIOS and specifically NETBIOS broadcast, is used for name resolution.   This is because most sites in a Workgroup setup are not going to setup a WINS, nor are they going to do proper setup to use DNS for the type of name resolution that CIFS needs.
0
 

Author Comment

by:kcn
ID: 26202637
Chris .

On your below reply :-
3. Yep. Before ping can begin sending ICMP the name must be resolved to an IP. Only after that has happened does Ping start to do its real job.

==> which protocol resolve the name to IP when we PING ? ( if WINS Server is absent ) ???

0
 
LVL 71

Expert Comment

by:Chris Dent
ID: 26202662
DNS if DNS can and is there, otherwise NetBIOS Broadcast will be used for single-label names (like hostname, rather than hostname.domain.com). Of course, that will only apply if NetBIOS is enabled (it is by default).

Chris
0
 

Author Comment

by:kcn
ID: 26202912
Chris / giltjr

(1) So , In workgroup network , when I  "PING hostname" ( single-label name ) , NetBIOS ( default enable) is the one which resolve the hostname ( single-label name ) but NOT the WINS service because I never yet to enable / configure  WINS service  ????  WINS service is not default enable ??

By the way ,  please correct the my following understanding if I confuse in somewhere :-

(2) "when Microsoft TCP/IP is installed under XP Pro or server 2003 , the WINS client software + NetBIOS broadcast are  installed automatically. And by default, the NetBIOS broadcast service is enable BUT the WINS service need to be setup manually ?????

(3) To setup WINS service , we need to go to TCP/IP Properties > Advanced button > WINS Tab  > Add in WINS Address ???   Is this WINS address can be same as the workstation itself , or, we need to have physical separate WINS Server ?

Please answer in (1) , (2) and (3) , based on my questions .. Thanks
0
 
LVL 71

Accepted Solution

by:
Chris Dent earned 2000 total points
ID: 26203009

1.

NetBIOS - Enabled by default
WINS - Requires you to get a server, install the service and set everyone up to use it

2.

WINS, as a server, can only be installed under the server OS, so 2003 has it as an option (as does 2008). You're right though, manual installation.

Both XP and 2003 can use WINS as a client to help them with NetBIOS name resolution (not all servers would need the WINS server itself installed).

3.

Separate WINS server.

In a simple way WINS is like DNS. It's a server with a list of names, and it can reply to clients with those. WINS, in the same way as DNS, must be installed as a service for anyone to make use of it.

Chris
0
 

Author Closing Comment

by:kcn
ID: 31673961
Helpful and fast response
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This is a little timesaver I have been using for setting up Microsoft Small Business Server (SBS) in the simplest possible way. It may not be appropriate for every customer. However, when you get a situation where the person who owns the server is i…
The password reset disk is often mentioned as the best solution to deal with the lost Windows password problem. In Windows 2008, 7, Vista and XP, a password reset disk can be easily created. But besides Windows 7/Vista/XP, Windows Server 2008 and ot…
This video Micro Tutorial explains how to clone a hard drive using a commercial software product for Windows systems called Casper from Future Systems Solutions (FSS). Cloning makes an exact, complete copy of one hard disk drive (HDD) onto another d…
With the advent of Windows 10, Microsoft is pushing a Get Windows 10 icon into the notification area (system tray) of qualifying computers. There are many reasons for wanting to remove this icon. This two-part Experts Exchange video Micro Tutorial s…

830 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question