With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cpaeGuestVlanId
Cisco Port Access Entity Guest Vlan Id
1.3.6.1.4.1.9.9.220.1.2
Specifies the Guest Vlan of the system. An interface with cpaePortMode value of 'singleHost' will be moved to Guest Vlan if the supplicant on the interface is not IEEE-802.1x capable. A value of zero indicates no Guest Vlan configured in the system. If the platform supports per-port guest Vlan ID configuration, this object is not instantiated.
Back to CISCO-PAE-MIB MIB page.
IPHost Network monitor allows you to monitor cpaeGuestVlanId on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.