With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cIpLocalPoolStatInUseAddrs
Cisco Ip Local Pool Stat In Use Addrs
1.3.6.1.4.1.9.9.326.1.3.1.1.2
The number of IP addresses being used in this IP local pool.
Back to CISCO-IP-LOCAL-POOL-MIB MIB page.
IPHost Network monitor allows you to monitor cIpLocalPoolStatInUseAddrs on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.