With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrIpFragFails
Virtual Router Ip Frag Fails
The number of IP-fragments that have been discarded because they needed to be fragmented but could not be. For example, their Don't Fragment flag was set. fragFails wraps to zero if reaches its maximum defined value.
Back to Nortel-Magellan-Passport-IpMIB MIB page.
IPHost Network monitor allows you to monitor vrIpFragFails 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.