(ongoing) Netbios Name Resolution problem ...

[Guest]

How do the segment/domain master browser machines play into the name resolution scheme of things ? We have been having ongoing problems with Netbios name resolution on our Win2K Svr PDC. After making a change and disabling a few of its nics so that it would no longer be multihomed, the Netbios name resolution still resolves its name/path ( e.g. \\servername ) to the disabled IP addresses on the now-remote subnets. The WINS and DDNS databases are updated to only reflect the PDC's current IP address, and there are no entries in the lmhosts or hosts files on the clients. The clients are configured for Hybrid Netbios resolution, but Peer was also tried. After clearing the DNS, ARP, and NBTStat caches and running a network trace from a client, when ping'ing the PDC it appears that another client machine ( segment master browser ? ) is answering a NS query w/ the outdated IP address info for the PDC. Can this happen ? And, if so, how does one fix this problem ? We have tried to disable the Computer Browser Service on the clients ( to hopefully 'force' it to use WINS directly ) but this did not help. Is it just a matter of shutting-off every client PC on the entire lan, rebooting the server, and then trying again if it is in fact a Browser Service problem ? Or is there some way to 'flush' the master browser entries ? TIA for any help as it would be greatly appreciated ...

 

[David Dickinson]

Some resources I've used:

KB Article 818092 (the NetBIOS Browsing Console tool)

Webcast: Using the NetBIOS Browsing Console to Troubleshoot NetBIOS Browsing
http://support.microsoft.com/servic...ervicedesks/webcasts/en/WC061003/manifest.xml

General KB Articles: 102878, 136712, 150800, 188001, 820914

Browser Troubleshooting: 188305, 227419, 280374, and 285035

Incidentally, if I understand your configuration correctly, the Computer
Browser service /must/ be enabled. Also, make sure that RestrictAnonymous
is /not/ set to 2 (see 246261).

 

[Guest]

Cool, great resources ! I am going to download that browsing console now (which should really help), check the KB articles, and check that registry value as well. Thanks again for the help, I really appreciate it.

 

[Steven L Umbach]

Hi again.

Master browsers have nothing to do with name resolution, they only collect and
distribute the browse list which is nothing more than a gui for users to see what
computers/shares are available on the network. Once a user tries to access a
resource, then the name resolution process begins. Now a computer that is a master
browse could also be a dns or wins server in which case they could be used in the
name resolution process but a computer that is a separate process from browsing.

When you ping a computer by name, then the computer returning the IP address must be
a wins [possibly wins proxy] or dns server. That is where I would look to see why
that computer is returning a bad IP by looking in the dns zone or wins database on
that computer, and also hosts, lmhosts files. When you cleared the wins database you
should tombstone entries instead of deleting them or old entries can reappear if you
deleted them on the wins server that was not the owner that originally registered the
record. A dns server can also use wins lookup if it can not find the name in the dns
zone if configured for wins lookups so it can be trick to track the problem down.

Below is a paste from Ethereal to show how the name resolution process works on a
domain computer. I pinged a non existent computer named "server33" from computer with
IP address of 192.168.1.22 and you can see that first dns name resolution was tried,
followed by wins server, and finally three broadcasts as shown by address of
192.168.1.255 which did not find the non existent computer. --- Steve

source destination
4 192.168.1.22 192.168.1.105 DNS Standard query A
server33.umbach1.com
5 192.168.1.105 192.168.1.22 DNS Standard query response, No
such name
6 192.168.1.22 192.168.1.105 NBNS Name query NB SERVER33<00>
7 192.168.1.105 192.168.1.22 NBNS Name query response
8 192.168.1.22 192.168.1.255 NBNS Name query NB SERVER33<00>
9 192.168.1.22 192.168.1.255 NBNS Name query NB SERVER33<00>
10 192.168.1.22 192.168.1.255 NBNS Name query NB SERVER33<00>

How do the segment/domain master browser machines play into the name resolution

scheme of things ? We have been having ongoing problems with Netbios name resolution
on our Win2K Svr PDC. After making a change and disabling a few of its nics so that
it would no longer be multihomed, the Netbios name resolution still resolves its
name/path ( e.g. \\servername ) to the disabled IP addresses on the now-remote
subnets. The WINS and DDNS databases are updated to only reflect the PDC's current
IP address, and there are no entries in the lmhosts or hosts files on the clients.
The clients are configured for Hybrid Netbios resolution, but Peer was also tried.
After clearing the DNS, ARP, and NBTStat caches and running a network trace from a
client, when ping'ing the PDC it appears that another client machine ( segment master
browser ? ) is answering a NS query w/ the outdated IP address info for the PDC. Can
this happen ? And, if so, how does one fix this problem ? We have tried to disable
the Computer Browser Service on the clients ( to hopefully 'force' it to use WINS
directly ) but this did not help. Is it just a matter of shutting-off every client
PC on the entire lan, rebooting the server, and then trying again if it is in fact a
Browser Service problem ? Or is there some way to 'flush' the master browser entries
? TIA for any help as it would be greatly appreciated ...

 

[David Dickinson]

Now a computer that is a master

browse could also be a dns or wins server in which case they could be used in the
name resolution process...

Please note, however, that it is not necessary to have a WINS /or/ a DNS
server on the network in order to use NetBIOS "name resolution". In fact,
in my experience, NOT having a WINS server makes things simpler; if your
network requires a DNS server, then that should be all you have to worry
about.

When you ping a computer by name, then the computer returning the IP address must
be a wins [possibly wins proxy] or dns server.

If there is not a WINS or DNS server on the network, then the computer which
returns the IP address is the computer which is named in the ping command.
However, you might configure the LMHOSTS file on each machine, in which case
the local machine resolves the name before the actual ping request is sent.
However, a properly configured DNS server makes this unnecessary (and life
much easier).

 

[Steven L Umbach]

Of course wins or dns are not required for netbios name resolution per my description
of broadcasting for name resolution. However for networks with more then one segment,
wins will make network browsing much more reliable and for using downlevel clients to
find resources including the domain controllers. For a network of all W2K/W2003/XP
Pro computers on a single segment, AD dns will work just fine if configured
correctly. --- Steve

Now a computer that is a master
browse could also be a dns or wins server in which case they could be used in the
name resolution process...

Please note, however, that it is not necessary to have a WINS /or/ a DNS
server on the network in order to use NetBIOS "name resolution". In fact,
in my experience, NOT having a WINS server makes things simpler; if your
network requires a DNS server, then that should be all you have to worry
about.

When you ping a computer by name, then the computer returning the IP address must
be a wins [possibly wins proxy] or dns server.

If there is not a WINS or DNS server on the network, then the computer which
returns the IP address is the computer which is named in the ping command.
However, you might configure the LMHOSTS file on each machine, in which case
the local machine resolves the name before the actual ping request is sent.
However, a properly configured DNS server makes this unnecessary (and life
much easier).