With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
docsIfCmCmtsAddress
DOCSIS If Cm Cmts Address
1.3.6.1.4.1.2011.2.25.127.1.2.1.1.1
Identifies the CMTS that is believed to control this MAC domain. At the CM, this will be the source address from SYNC, MAP, and other MAC-layer messages. If the CMTS is unknown, returns 00-00-00-00-00-00.
Back to DOCS-IF-MIB MIB page.
IPHost Network monitor allows you to monitor docsIfCmCmtsAddress on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.