With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cpaeHostInfoUserName
Cisco Port Access Entity Host Info User Name
1.3.6.1.4.1.9.9.220.1.11.1.4
Indicates the name of the authenticated user on the host.
Back to CISCO-PAE-MIB MIB page.
IPHost Network monitor allows you to monitor cpaeHostInfoUserName 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.