With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
vlanPortIslVlansAllowed
vlan Port Isl Vlans Allowed
1.3.6.1.4.1.9.5.1.9.3.1.5
on this Inter-Switch Link. This is an octet string value with bits set to indicate allowed VLANs. It can be interpreted as a sum of f(x) as x goes from 0 to 1023, where f(x) = 0 for VLAN x not allowed and f(x) = exp(2, x) for VLAN x allowed.
Back to CISCO-STACK-MIB MIB page.
IPHost Network monitor allows you to monitor vlanPortIslVlansAllowed 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.
