With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
docsDevCpeInetSource
DOCSIS Device Cpe Inet Source
1.3.6.1.2.1.69.1.7.4.1.3
This object describes how this entry was created. If the value is manual(2), this row was created by a network management action (either configuration or SNMP set). If set to learned(3), then it was found via looking at the source IP address of a received packet.
Back to DOCS-CABLE-DEVICE-MIB MIB page.
IPHost Network monitor allows you to monitor docsDevCpeInetSource on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.