I had the same question and ended up creating and using a custom TA for our Windows 2008 R2 based DHCP servers.
It's rather simple. It's a scripted input which runs on those DHCP host via their universal forwarder and performs:
netsh dhcp server show mibinfo
This shows all scopes, number of addresses in use/free and pending offers for the DHCP server which I then index in Splunk.
The information is little all over the place, at least in my case. 🙂
I get mine from Active Directory and then correlate them together.
So for example, from the output of
netsh dhcp server show mibinfo:
Subnet = 10.11.12.0. No. of Addresses in use = 0. No. of free Addresses = 1. No. of pending offers = 0.
And the following from my Active Directory entries for subnets (Base DN="CN=Subnets,CN=Sites,CN=Configuration,DC=your,DC=company,DC=com", Filter="(&(objectClass=subnet))"):
siteObject,name,description "MY_SITE_CODE","10.11.12.0/24","My Company Site ABC Scope"
Note: You can use SA-LDAPSearch to query your Active Directory or a custom script (I use perl).
Then you should be able to get the scope IP range, the site (or whatever) it belongs to and a nice description for it.