With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cVrrpOperationsMasterIpAddr
Cisco Vrrp Operations Master Ip Addr
1.3.6.1.4.1.9.10.999.1.7.1.9
The master router's real IP address. This is the IP address listed as the source in VRRP advertisement last received by this virtual router.
Back to CISCO-IETF-VRRP-MIB MIB page.
IPHost Network monitor allows you to monitor cVrrpOperationsMasterIpAddr 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.