De fragmentation

In a windows 2003 environment, if you low on disk space, or if you have deleted a lot of objects since you promote your DC. You should perform an offline degragmentation to the DIT file. As you might know, there are two type of defragmentation in windows 2003 family,
- online Defragmentation
- offline Defragmentation

Online Defragmentation

By default in windows 2003, the online defrag process runs every 12 hours on each domain controller. This process defrags the Active Directory database (ntds.dit) by combining whitespace generated from deleted objects, but does not reduce the size of the database file.
you can check the Directory Event log to see when the last online defrag was performed. See Figure-1 for NTDS online Defrag Event 700 (Online Defrag start) in Directory Service log indicates the online Defrag has started.

Figure-1 NTDS online Defrag Event 700 (Online Defrag started)

upon completion of Online defrag, an event number 701 is logged. See Figure-2

Figure-2 NTDS online Defrag Event 701 (Online Defrag Ended)

You can also manually start the online Defrag, here is how:
1. Start => Run => "LDP" to start up LDP
2. Select Connection => Connect, enter name of Domain controller with Default Port 389
3. Connection => bind, then enter admin credential

Figure-3 Bind with Admin Credential
4. Browse => Modify,
   - Leave DN Blank
   - For Attribute, enter " DoOnlineDefrag"
   - Value enter Maximum time(SEC) the defrag should run, here we use  180
   - For Operation, choose Add,
   - click enter

Figure-4 Add DoOnlineDefrag Attribute to trigger the online Defrag
5. click Run

Offline Defragmentation

Beside online defragmentation which is performed automatically at default interval of 12 Hours as part of Windows Maintenance(Garbage Collection), offline defragmentation create compacted version of database file which in most case will be considerably smaller. here is how you can start offline defrag:
1. you need to first reboot the server into DS restore mode, please see "How to perform a Nonauthoritative Restore to Domain Controller? "  for more detail on how to boot to DS Restore mode.
2. Check Directory Integrity, detail see "How to check Active Directory database integrity(DIT File's Integrity)? "
3.  Open up command prompt and type ntdsutil
4. goto files menu
5. issue command " compact to C:\TempFolder, you can use single command too:
ntdsutil files "compact to P:\TempFolder"
See Figure-5 for output of compact subcommand

Figure-5 Compact to C:\TempFolder output
6. next you need to delete the Transcation Log files in the current NTDS directory.
   del C:\WINDOWS\NTDS\*.log 
7. Next to move the dit file in the temperory folder to original directory, it's recommended to rename the original DIT file and store in the temperory location to ensure nothing "Strange" happened to compacted DIT.
Below command is to move and rename the older DIT file to the temp folder
move c:\WINDOWS\NTDS\ntds.dit P:\TempFolder\ntds_old.dit
next, move new ntds.dit file to windows\ntds directory:
move P:\TempFolder\ntds.dit C:\WINDOWS\NTDS\ntds.dit
8. Now we need to run another integrity check of DIT file.(refer to step 2)

DHCP Server Icons - List

In DHCP Console We do have different icons re

Server-related icons

Icon	Description
	DHCP server added to console.
DHCP server connected (active)	DHCP server connected and active in console.
DHCP server connected (inactive)	DHCP server connected but not authorized in Active Directory for use on your network.
DHCP server Not Loaded	DHCP server connected but current user does not have the administrative credentials to manage the server.
DHCP server Warning	DHCP server warning. Available addresses for server scopes are 90 percent or more leased and in use. This means that the server is nearly depleted of available addresses to lease to clients.
DHCP server Alert	DHCP server alert. No addresses are available from server scopes because the maximum (100 percent) of the addresses allocated for use are currently leased. This represents a failure of the DHCP server on the network because it is not able to lease or service clients.

Scope-related icons

Icon	Description
Scope or Superscope Active	Scope or superscope is active.
Scope or superscope is inactive.	Scope or superscope is inactive.
Scope Warning	Scope or superscope warning. Scope warning: 90 percent or more of the scope's IP addresses are in use. Superscope warning: If any scope within the superscope has a warning, the superscope has a warning.
Scope Alert	Scope or superscope alert. Scope alert: All IP addresses have been allocated by the DHCP server and are in use. No more clients can obtain IP addresses from the DHCP server because it has no more IP addresses to allocate. Superscope alert: At least one scope contained in the superscope has all IP addresses allocated by the DHCP server. No clients can obtain an IP address from the range defined in the scope that is 100 percent allocated. If other scopes within the superscope contain available addresses, the DHCP server can allocate addresses from these scopes.

Option-related icons

Icon	Description
Server options folder	Server options folder.
Server option	Server option.
Scope options folder	Scope options folder.
Scope option	Scope option.
Reservation option	Reservation option.

Other console icons

Icon	Description
	Root of the DHCP console.
Address pool folder	Address pool folder.
Scope allocation range	Scope allocation range. Addresses in this range are allocated to the available address pool used to offer leases to clients.
Scope exclusion range	Scope exclusion range. Addresses in this range are excluded from the available address pool used to offer leases to clients.
Active leases folder	Active leases folder.
Client, LAN-based	Active lease: this address is not available for lease by the DHCP server.
Client not registered.	Expired lease: this address is available for lease by the DHCP server.
Client active and registered.	Active lease, DNS dynamic update pending. This address is not available for lease by the DHCP server.
Client using remote access	Client is using dial-up network connection through a remote access server.
Reservations folder	An individual reservation and the reservations folder.
BOOTP table	Bootstrap Protocol (BOOTP) table.
BOOTP entry in table	BOOTP entry in the table.

Source : http://technet.microsoft.com/en-us/library/cc784812(WS.10).aspx