With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrIpxNetworkNumber
Virtual Router Ipx Network Number
This attribute indicates the internal network number portion of the IPX address. This network number must be unique within the internetwork and is necessary to determine master/slave relationships during IPXWAN negotiations.
Back to Nortel-Magellan-Passport-IpxMIB MIB page.
IPHost Network monitor allows you to monitor vrIpxNetworkNumber 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 switches right now.