With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrPpSrtBpSegmentMismatchDiscards
Virtual Router Passport Srt Bridge Port Segment Mismatch Discards
This attribute specifies the number of All Routes Explore and Spanning Tree Explore frames that were discarded due to an invalid next segment value in the routing information field. This counter will wrap to zero when it exceeds its maximum.
Back to Nortel-Magellan-Passport-BridgeMIB MIB page.
IPHost Network monitor allows you to monitor vrPpSrtBpSegmentMismatchDiscards on Allied Telesis device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Nortel multiplexers right now.