With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
mplsInterfacePerfOutFragmentedPkts
mpls Interface Perf Out Fragmented Packets
1.3.6.1.3.96.1.2.1.4
This object counts the number of outgoing MPLS packets that required fragmentation before transmission on this interface. This object MUST count on a per-interface basis regardless of which label space the interface participates in.
Back to MPLS-LSR-STD-MIB MIB page.
IPHost Network monitor allows you to monitor mplsInterfacePerfOutFragmentedPkts 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.
