With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cseRouterVlan
CISCO SWITCH ENGINE Router Vlan
1.3.6.1.4.1.9.9.97.1.2.6.1.2
The Vlan number associated with the router's MAC address.
Back to CISCO-SWITCH-ENGINE-MIB MIB page.
IPHost Network monitor allows you to monitor cseRouterVlan on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.