Note: In Windows Server 2008 R2, active leases can be converted to reservations by just doing a right click in the DHCP Server management console. :)
If anyone is interested…or needs this in the future:
1. Dump all leases:
Netsh dhcp server scope 192.168.1.0 show client
2. import the output (after cutting the first descriptional lines) to an excel file as space delimited file, remove unnecessary infos (i.e. “-” from the MACs and the unnecessary columns), then export to a file so that only the following info is retained in the file:
3. add reservation for all clients: create a script which processes the lines of the output file and executes:
Netsh dhcp server scope 192.168.1.0 add reservedip IP MAC
(here the IP and the MAC should come from the outputfile)
Script to read from file and create reservation (without error checking):
Const TEST_FILE_PATH = "C:\ip-mac.txt"
Set objFileSystemObject = CreateObject("Scripting.FileSystemObject")
'Open our file
Set objOurExistingFileStream = objFileSystemObject.OpenTextFile(TEST_FILE_PATH)
Set oShell = WScript.CreateObject ("WSCript.shell")
'Read out the file-content
Do Until objOurExistingFileStream.AtEndOfStream
'each line contains an Ip and a MAC
strLine = objOurExistingFileStream.ReadLine
myComm = "%COMSPEC% /c Netsh dhcp server scope 192.168.1.0 add reservedip " + strLine +" >>c:\DhcpReservation.log"
Set objOurExistingFileStream = Nothing
Set objFileSystemObject = Nothing
Set oShell = Nothing
and finally logs will be available at c:\DhcpReservation.log for verification & validation.
NOTE: Thanks to Mr.Balint who has shared the Script with US.
thanks, I had a type mismatch vbs error on the final strLine entry. I added 'on error resume next' at the beginning and all worked OK.
If you wanted to put a reservation name and description in as well, how do you do this?
Wish List Item: It would be great if you could just right click on an active lease in the management tool and select "Convert to reservation"!
Your wish has been granted :) . You can convert active leases to reservations easily by doing a right click in Windows Server 2008 R2 Beta DHCP Server.
DHCP Server Team