With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
tn3270eTcpConnLocalAddress
tn3270e Tcp Connection Local Address
1.3.6.1.2.1.34.8.1.9.1.5
The local address associated with a TN3270E client. tn3270eTcpConnRemAddrType indicates the address type (IPv4 or IPv6, for example).
Back to TN3270E-MIB MIB page.
IPHost Network monitor allows you to monitor tn3270eTcpConnLocalAddress 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.