With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swISMVlanRepSourceAddr
Switch ISM Vlan Rep Source Address
1.3.6.1.4.1.171.12.64.3.1.1.9
This is the replacement address of this multicast VLAN.
Back to MCAST-VLAN-MIB MIB page.
IPHost Network monitor allows you to monitor swISMVlanRepSourceAddr on D-Link device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring D-Link switches right now.