With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swL2VlanForbiddenPorts
Switch L2 Vlan Forbidden Ports
1.3.6.1.4.1.171.11.70.5.2.17.1.1.8
The set of ports which are prohibited by management from being included in the egress list for this VLAN. Changes to this object that cause a port to be included or excluded affect the per-port per-VLAN Registrar control for Registration Forbidden for the relevant GVRP state machine on each port. A port may not be added in this set if it is already a member of the set of ports in dot1qVlanStaticEgressPorts. The default value of this object is a string of zeros of appropriate length, excluding all ports from the forbidden set.
Back to DGS3650-L2MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor swL2VlanForbiddenPorts 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 VPN routers right now.