With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
pnniSummaryAddressPrefixLength
pnni Summary Address Prefix Length
1.3.6.1.4.1.353.5.4.1.1.20.1.3
The prefix length for the summary.
Back to PNNI-MIB MIB page.
IPHost Network monitor allows you to monitor pnniSummaryAddressPrefixLength 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.