Don't Give Me Any Static
How to automate the process of modifying a slew of statically mapped WINS servers.
- By Bill Boswell
I'm feeling a bit red-faced after
. If you recall, a reader had a problem with a USB
thumb drive. He saw the contents of a mapped drive when he should have
seen the contents of the thumb drive. I didn't know the cause so I advised
dragging out a deep diagnostic tool called Winobj http://www.sysinternals.com/ntw2k/freeware/winobj.shtml
and other complicated things to look for the source of the problem. I
also asked for help.
Well, I received many, many replies from all around the world telling
me that I had made the problem much too complicated. It turns out that
the removable drive was simply taking the next available drive letter
and "stepping on" an existing network drive mapping.
Here are the Admin All Stars who wrote in with the solution to the USB thumb
drive content problem. Thanks to all of you!
Admin All Stars
| Carson Wells
The first respondent was Michael Dreisbaugh, and he won a highly coveted MCPMag
Now for this question from an anonymous reader:
We're installing a couple of new WINS servers and now I face the
task of modifying the WINS information in 150 servers with static TCP/IP
configuration. Any suggestions how to automate this?
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I have a couple of methods that I've used when making this sort of global
change to server IP settings. To be honest, though, I like the "Just
Say No" approach. Rather than change the statically mapped TCP/IP
settings on the servers, just configure the network interface to use DHCP.
Then you can change the WINS entries (or DNS, for that matter) in the
DHCP scope options and just wait for the clients to renew their addresses
to get the new settings.
"But wait," you say, "How will my clients find the servers
if the server's IP addresses keep changing?"
Well, Windows 2000 and Windows Server 2003 servers will dynamically update
their IP addresses in DNS and in WINS, so you don't have a problem in
But, you might have NT servers or Samba servers that don't dynamically
update DNS. In that case, you could use a feature in Windows DHCP to update
a DHCP client's A and PTR records in DNS when leasing an address.
Also, all your work processes must use DNS names rather than static IP
addresses. If you have a developer or fellow admin who embedded a static
address in some code or a configuration table, then you’ll be spending
a while doing some debugging.
If you really don't want your servers' IP addresses to change, but you
still want the flexibility to use DHCP scope options to control TCP/IP
settings, you can reserve the server's lease in DHCP. This reservation
uses the MAC address of the server's NIC as a unique identifier. If a
server has multiple NICs, you can use multiple reservations.
In the end, you may decide that DHCP just isn't an option for your servers
and you want to change the static settings remotely. Even if you do want
to change over to DHCP, you face the job of changing the configuration
for every server.
TCP/IP settings are stored in the Registry, but changing them turns out
to be something of a trick because each interface stores its parameters
under a key with a unique ID number. Here's an example:
EnableDHCP REG_DWORD 0x0
NameServer REG_SZ 10.0.0.254
Domain REG_SZ company.com
RegistrationEnabled REG_DWORD 0x1
RegisterAdapterName REG_DWORD 0x1
To change the settings without knowing the UID, you can use Windows Management
Instrumentation (WMI). Here's a brief VBScript example that takes the
server names from a file called "serverlist.txt" and uses it
to enable DHCP on the active network interface:
Set fso = CreateObject("Scripting.FileSystemObject")
Set fh = fso.OpenTextFile("c:\scripts\serverlist.txt",1)
Do While Not fh.AtEndOfStream
WScript.Echo vbCrLf & String(20,"*")
computerName = fh.ReadLine()
Set wmiObj = GetObject(
computerName & "\root\cimv2")
Set nicList = wmiObj.ExecQuery (
* FROM Win32_NetworkAdapterConfiguration
IPEnabled = True")
For Each nic In nicList
If nic.DHCPEnabled Then
already enabled on "
nic.Caption & " for " & computerName & "."
DHCP on " & nic.Caption
& " for
" & computerName & "."
Whoa! You'll want to do some experimenting before you unleash
this script on your production network. For example, you might have servers
with two live interfaces, one for the production side and one for backup.
This script would convert both interfaces to DHCP and the backups will
fail. You can avoid this by only applying the DHCPUpdate method to interfaces
where the first couple of octets in the nic.IPAddress property match the
There are similar potential problems with VMware virtual adapter settings,
VPN endpoint settings, and others. Choose your targets carefully.
If you have static settings and just want to change the WINS properties,
you can use a similar script to access the Win32_NetworkAdapterConfiguration
properties of the interface. then change these two properties:
If you want to see all the WMI properties, use WMIC with the following
wmic path win32_networkadapterconfiguration get * /format:list
To use WMI to manage NT servers, you'll need to install the most current
WBEM drivers on the servers. The WBEM files for NT4 are included in the
WMICore download at http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=AFE41F46-E213-4CBF-9C5B-FBF236E0E875.
Until next week!
Contributing Editor Bill Boswell, MCSE, is the principal of Bill Boswell Consulting, Inc. He's the author of Inside Windows Server 2003 and Learning Exchange Server 2003 both from Addison Wesley. Bill is also Redmond magazine's "Windows Insider" columnist and a speaker at MCP Magazine's TechMentor Conferences.