With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cbgpRouteAddrPrefixLen
CISCO BGP4 Route Address Prefix Length
1.3.6.1.4.1.9.9.187.1.1.1.1.6
Length in bits of the Network Address prefix in the Network Layer Reachability Information field.
Back to CISCO-BGP4-MIB MIB page.
IPHost Network monitor allows you to monitor cbgpRouteAddrPrefixLen 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.