Monitor Free or Available DHCP Lease Values
Scenario: I have a windows 2003 Based DHCP server. We have a queue that needs to be monitored to make sure it doesn't run out of inactive leases. Is there a way to set a minimum available inactive leases and notify a group of users when that threshold is met? Solution:
Within the context of this question, you can utilize the IPSentry SNMP Add-In component and monitor minimums, maximums, changes, delta changes, and etc. for the following DHCP values within a specific DHCP Scope. noAddFree: This no. of addresses that are free noAddInUse: This is the no. of addresses in use To accomplish this, you will want to import the DHCP-MIB using the "Import MIB" feature of the SNMP Add-in. Download: http://download.ipsentry.com/SNMPMIBS/DHCP-MIB.zip Unzip the DHCP-MIB.mib to your mib files folder and import. In the SNMP Add-in, browse to and highlight: iso.org.dod.internet.private.enterprises.microsoft.software.dhcp.dhcpScope Select Edit, Walk MIB In the "Walked" tab, locate and expand scopeTable.scopeTableEntry You will notice the noAddFree, noAddInUse. When you expand them, you will there will be a tree for the DHCP scope (e.g. 192 / 168 / 1 if DHCP scope is 192.168.1.0 255.255.255.0 ) Now, you can setup a an SNMP filter on the final value to alert you if the noAddFree or noAddInUse are outside of your specifications. e.g. Set the filter for noAddFree to alert you if the value is not greater than 10 so that you know you will be alerted if you only have 10 free addresses available within the scope address scope. Then, setup your alerting functions to notify the appropriate persons (email, cell, etc...) allowing a response before the DHCP leases are exhausted.