code:

---

Break ON
   
; Set address list to all the hosts you want to monitor.
$asAddressList="130.11.21.1","10.0.0.2","steed.sgb.co.uk"
   
Dim $aiStatus[UBound($asAddressList)+1]
   
$iInterval=60				; Number of seconds between checks
$sSound="c:\windows\media\chimes.wav"	; Path to sound to play
   
While "true"
   $sMessage=""
   For $iIndex=0 To Ubound($asAddressList)
      $sAddress=$asAddressList[$iIndex]
      $iStatus=$aiStatus[$iIndex]
      If fnMonitorIP($sAddress)
         If $iStatus
            $sMessage=$sMessage+@TIME+" Address " + $sAddress + " is now unavailable." +@CRLF
	 EndIf
	 $aiStatus[$iIndex]=0
      Else
	 If $iStatus=0
            $sMessage=$sMessage+@TIME+" Address " + $sAddress + " is responding." +@CRLF
	 EndIf
	 $aiStatus[$iIndex]=1
      EndIf
   Next
   If $sMessage <> ""
      Play $sSound
      $sMessage
      $Null=MessageBox("$sMessage","Change in monitored station status",0,5)
   EndIf
   Sleep($iInterval)
Loop
   
Function fnMonitorIP($sAddress)
   Shell '%COMSPEC% /C ping -n 1 ' + $sAddress + ' >/dev/null'
   $fnMonitorIP=@ERROR
   Return
EndFunction

---

• The message and sound are only displayed once for each workstation as it comes onto the network.
• An alert is displayed when a monitored workstation is removed from the network, and an alert will be subsequently displayed if it re-appears.

code:

---

10,02/21/03,12:55:07,Assign,10.17.16.46,SGB-5938,0080640C96BC
11,02/21/03,12:56:53,Renew,10.17.20.21,SGB-07772,0000397100B9

---

As you can see, two machines (SGB-07772 and SGB-5938) have leased IP addresses, one a renewal and the other an assign.

There is also a DHCP query tool available in the NT resource kit which will dump the database.

If your DHCP servers are Cisco routers or Access serves or similar, you're on your own