With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cempMemPoolUsed
Cisco Enhanced Memory Pool Used
1.3.6.1.4.1.9.9.221.1.1.1.1.7
Indicates the number of bytes from the memory pool that are currently in use by applications on the physical entity.
Back to CISCO-ENHANCED-MEMPOOL-MIB MIB page.
IPHost Network monitor allows you to monitor cempMemPoolUsed on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.