What is the result of packets that are created which exceed the MTU of the network?  How can this process be exploited?

What will be an ideal response?

Packets that are larger than the MTU must be fragmented, or broken into multiple segments that are small enough for the network to handle.

After a packet is broken into fragments, each fragment receives its own IP header. However, in IPv4, only the initial packet in a set includes a header for higher-level protocols. Most filters need the information in the higher-level protocol header to make the decision to allow or deny the packet. Accordingly, attackers send only secondary fragments, which are any fragments other than the initial one. These packets are often allowed past the IDPS because filter rules are applied to first fragments only.