IP4 Normalizations

IP4 normalizations are enabled with:

    preprocessor normalize_ip4: [df], [rf], [tos], [trim]

Base normalizations enabled with "preprocessor normalize_ip4" include:

• TTL normalization if enabled (explained below).

• Clear the differentiated services field (formerly TOS).

• NOP all options octets.

Optional normalizations include:

• df don't fragment: clear this bit on incoming packets.

• rf reserved flag: clear this bit on incoming packets.

• tos type of service (differentiated services): clear this byte.

• trim truncate packets with excess payload to the datagram length specified in the IP header + the layer 2 header (eg ethernet), but don't truncate below minimum frame length. This is automatically disabled if the DAQ can't inject packets.