With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
pnniMapNodePreferredPgl
pnni Map Node Preferred Pgl
1.3.6.1.4.1.353.5.4.1.1.15.1.10
Identifies the node which the originating node believes should be or is peer group leader of its peer group. If the originating node has not chosen a Preferred PGL, this attribute's value is set to (all) zero(s).
Back to PNNI-MIB MIB page.
IPHost Network monitor allows you to monitor pnniMapNodePreferredPgl 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.