Naming problems. DNS?

  • Thread starter Thread starter The CQMMAN
  • Start date Start date
T

The CQMMAN

Hello,

We are having a few problems within our site. Lets say I am trying to
get hold of a workstation called WKS1.

I can't connect via UNC to the name, but if I ping it, I get a
response back from an IP address. If I then connect to the IP address,
I can see that it is not WKS1, but a different workstation. The
response to the ping is coming back with a FQDN so must be from DNS
rather than WINS. At it happens, WKS1 is not even in the office
because it is a laptop and the owner is away on holiday.

So, what is causing these resolution problems and what is the best way
to fix it? It really is unacceptable that either I or an application
which connects via name cannot be sure that it will connect to the
correct resource.

Any ideas? Things to check? The servers are running W2K and Microsoft
DNS (not integrated with AD) and the clients are W2K.

Cheers
 
Confused. WKS1 is not in office, yet you can ping it? Are you pinging his
machine over a WAN link and his machine is on. I know on w2k, when the dns
name is different then the NetBIOS name, there is some reg entry that can be
turned on to allow diff names (can't remember it offhand.)

--wjs mvp
 
Yep. WKS1 is not even switched on, but a ping to WKS1 is resolved because
DNS is returning an IP address of a different workstation. When I then try
and connect to "WKS1", I get an error about the account being locked out,
but when I connect to the IP address that was returned from the ping, I can
connect to a workstation, but it is certainly not WKS1.

We use DHCP, so I don't know if WKS1 ever had the IP address that DNS is
responding with (but it is possible), but something is surely not right.

The DNS names and netbios names are the same for each workstation.
 
Output would help here. Lets see:
1) ping wks1
2) ipconfig /all on your workstation
 
Go look at your DNS server and see if there is multiple
entries for WKS1. Sounds like that might be there issue
here.
 
N:\>ping WKS1

Pinging WKS1.LOCATION.COMPEMEA.INT [10.15.1.153] with 32 bytes of data:

Reply from 10.15.1.153: bytes=32 time<10ms TTL=128

Reply from 10.15.1.153: bytes=32 time<10ms TTL=128

Reply from 10.15.1.153: bytes=32 time<10ms TTL=128

Reply from 10.15.1.153: bytes=32 time<10ms TTL=128

Ping statistics for 10.15.1.153:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 0ms, Maximum = 0ms, Average = 0ms



Windows 2000 IP Configuration

Host Name . . . . . . . . . . . . : WKS112

Primary DNS Suffix . . . . . . . : LOCATION.COMPEMEA.INT

Node Type . . . . . . . . . . . . : Hybrid

IP Routing Enabled. . . . . . . . : No

WINS Proxy Enabled. . . . . . . . : No

DNS Suffix Search List. . . . . . : LOCATION.COMPEMEA.INT

compuk.com

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : compuk.com

Description . . . . . . . . . . . : Intel(R) PRO/100 VM Network Connecti

on

Physical Address. . . . . . . . . : 00-08-02-0B-D1-A7

DHCP Enabled. . . . . . . . . . . : Yes

Autoconfiguration Enabled . . . . : Yes

IP Address. . . . . . . . . . . . : 10.15.1.194

Subnet Mask . . . . . . . . . . . : 255.255.252.0

Default Gateway . . . . . . . . . : 10.15.0.1

DHCP Server . . . . . . . . . . . : 10.15.0.209

DNS Servers . . . . . . . . . . . : 10.15.0.212

Primary WINS Server . . . . . . . : 10.15.0.245

Lease Obtained. . . . . . . . . . : 12 January 2004 10:35:31

Lease Expires . . . . . . . . . . : 26 January 2004 10:35:31



If I connect to the workstation using the IP address (\\10.15.1.153), I
actually connect to a different workstation (not WKS1) so there is a problem
somewhere.

Cheers
 
Done a bit more digging.

There are no multiple entries in DNS, there are however multiple entries in
WINS. Basically WKS2 both have "active" records in WINS with the same IP
address.

So in this case, WKS2 doesn't have a DNS entry at all, it is being resolved
via WINS.

A couple of questions then:

1) Why doesn't WKS2 have a DNS entry? Shouldn't this be created
automatically? Can anyone suggest a place to look to see why this hasn't
happened?

2) Do I need to decrease some of the WINS internvals such as extinction
interval and timeout?

Thanks for all your help so far.
 
TC> So, what is causing these resolution problems
TC> and what is the best way to fix it?

The cause is that the contents of your DNS database don't match the actual IP
address assignments for your machines. This will be because

* You are using secure dynamic DNS updates and you are attempting to mix and
match ISC and Microsoft softwares.
* You are performing the DNS database updates by hand, and have forgotten to
perform at least one.
* You are using secure dynamic DNS updates, and you have only Microsoft
softwares throughout; but you've configured the DHCP clients rather than the
DHCP server to perform the DNS database updates as leases are granted and
revoked, you've forgotten to enable aging and scavenging, and when the laptop
was taken away it wasn't properly instructed to release its IP address lease
before being unplugged.

TC> It really is unacceptable that either I or an application which
TC> connects via name cannot be sure that it will connect to the
TC> correct resource.

Then don't use names. This is the state of affairs when it comes to using
names instead of IP addresses. There is no guarantee.
 
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