With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
tn3270sRemoteMacAddress
tn3270s Remote Mac Address
1.3.6.1.4.1.9.9.54.1.3.1.1.13
MAC address of the remote node; valid for direct PU only.
Back to CISCO-TN3270SERVER-MIB MIB page.
IPHost Network monitor allows you to monitor tn3270sRemoteMacAddress 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.