Migrating DHCP reservations from Novell to Microsoft

We are gradually migrating our core services from Novell Netware to Windows Server 2003 and 2008. As part of this migration we needed to migrate all our DHCP reservations stored on our Novell servers to Windows Servers.

First a comment, although Microsoft seems to have a much better DNS system than on Netware 6.5, their DHCP implementation leaves a lot to be desired.

On Novell I could create a scope, reservations and options and it is stored in eDirectory. I could then have multiple DHCP servers with different IP ranges to offer. I could use the java console (sometime slow) to add a reservation and it would sync to both servers.

On Windows Server 2003 and 2008 I need to separate create scopes, allocation ranges and reservations on each server. Their is no synchronisation or communication between these servers. This means to migrate my reservations from my current Netware DHCP servers to the target Windows servers the reservations need to be added to each server, as well as adding any future reservations to both servers.

Migration Process

First use the Novell DNS/DHCP console and export the DHCP scope / database you are migrating.

I have written the following Perl code to read in the DHCP3TAB file generated and output a netsh file that will add all your reservations to any number of Windows DHCP servers.

You will need to modify the DHCP servers list to your AD servers and change the scopeName to the correct IP settings.

After running your DHCP3TAB through the perl script, copy output to your server and run netsh exec outputFile.txt to add it to your servers.

#!C:\Perl\bin\perl.exe

# Designed to read in Rservations from a Novell DHCP Tab file and output a NetSH script file
# From http://technet.microsoft.com/en-us/library/cc787375.aspx
# On the destination server, the exec command is used to load and execute the converted reservations:
#  netsh exec AdReservations.txt
# After you use the exec command to load the file, you must reconcile all scopes. 
# Use net stop dhcpserver to stop the DHCP Server service and net start dhcpserver to restart it. Once the service is restarted, DHCP database changes take effect.

use strict; use warnings;

my $dhcptabName = "DHCP3TAB.txt";
my $outFile = "AdReservations.txt";
my @dhcpServers = ('\\\\DHCPServer1.win.us.schools.nsw.edu.au',
    '\\\\DHCPServer2.win.us.schools.nsw.edu.au');
my $scopeName = "10.10.11.0";

open F, "< $dhcptabName" or die "Can't open $dhcptabName : $!";
open O, "> $outFile" or die "Can't open $outFile : $!";
 
# File parsing
my $ip;
my $host;
my $mac;
my $type;
my $comment="";

while (my $line = <F>){
  if ($line =~ /^\[IP Address Configuration /i) {
  # New entry, clear values
    $ip="", $host="", $mac="", $type="", $comment="";
    
    while ((my $entry = <F>) !~ /^$/){
    # Parse and fill in values
      if ($entry =~ /IP Address Number = ([\d.]+)/i){
        $ip=$1;
      }
      elsif ($entry =~ /Assignment Type = (\d+)/i){
        $type=$1;
      }
      elsif ($entry =~ /Host Name = ([\w\-_]+)/i){
        $host=$1;
      }
      elsif ($entry =~ /MAC Address = 1 (.+)/i){
        $mac=$1;
        $mac=~ s/\s+//g;
      }
      elsif ($entry =~ /Comment = (.+)/i){
        $comment=$1;
      }
    }

    # Following determines which type of entries to convert. Default is only reservation. 
    # You can comment it out and uncomment the second line to include reservations and allocated IPs.
    # If  type != 8 (reservation) discard
    next unless ($type == 8); 

    # If  type != 8 (reservation) or  != 2 (Allocated) discard
    # next unless  ($type  == 8 or $type  == 2);

    next if ($mac eq "" or $ip eq "" or $host eq "");
    foreach my $server (@dhcpServers){
      print O "Dhcp Server $server Scope $scopeName Add reservedip $ip $mac \"$host\" \"$comment\" \"BOTH\"\n";
    }
  } 
}

close F;
close O;
Posted in Active Directory, Novell | Tagged , , , , , , , , , | 4 Comments

AD Password Reset and Bulk Modify

Those who in the past have used the Novell Change Pass utility may have been missing it when moving to Active Directory.

A great tool is Wisesoft Password Control which allows you to just type in the username, it will display info about the account and give you the option to change the password, enable/disable the account and unlock the account.
It is ideal to make available to teachers for resetting the student passwords if you use the Delegate control option in AD Users and Computers for your student OU’s.

The other useful tool on the website is a pair of tools Bulk Password Control and Bulk Modify. These allow you to bulk reset the password for a large group of students, or modify the attributes for a large number of users. It can read these in from a CSV file, and match the CSV entires to either sAMaccountName or some other user attribute. You can also set the attribute based on their existing attributes.

After downloading it will ask you for a code that you can get with a free registration on their site.

Posted in Active Directory, Utilities, Windows | Tagged , , , , , , , , , | Leave a comment

OverDisk

Recently I needed to identify where all the space was going on our server. Usually I just use the Folder Size tab extension but it requires scanning every time you close the Properties dialogue.

After looking around online I found a great free utility that displays the info in an easy to explore graphical view. OverDisk scans the drive or folder (this took around 10 mins for a drive containing hundreds of home directories) and then you can save the data so it does not need to constantly rescan (unless you make changes to files).You can also have it only rescan a certain subfolder rather than the entire drive again.

It presents the information in a colour coded pie chart, allowing you to easily see which folders and files are using the most space.

You can click on the folder and the pie chart will change to reflect that folder or click the middle of graph to go up a level. Right clicking on a folder gives you an easy option to Open or Explore in Explorer.

OverDisk folder space tool

Links:

Posted in Utilities, Windows | Tagged , , , , , , , | 2 Comments