The main purpose of the preprocessor is to perform SMB desegmentation and DCE/RPC defragmentation to avoid rule evasion using these techniques. SMB desegmentation is performed for the following commands that can be used to transport DCE/RPC requests and responses: Write, Write Block Raw, Write and Close, Write AndX, Transaction, Transaction Secondary, Read, Read Block Raw and Read AndX. The following transports are supported for DCE/RPC: SMB, TCP, UDP and RPC over HTTP v.1 proxy and server. New rule options have been implemented to improve performance, reduce false positives and reduce the count and complexity of DCE/RPC based rules.