Each ANIC adapter has a very powerful and flexible L2/L3/L4 packet parser. The header information from each packet that enters the system is extracted and processed to inform the host application about relevant packet details and also as input for packet filtering.
Tunneling and Encapsulation
The parser is able to recognize various tunneling and encapsulation protocols such as VLAN, VXLAN, MPLS, GTP and GRE. The adapter is then able to intelligently strip away the tunnel encapsulations and analyze the relevant packet information contained inside the tunnel.
If a host application does not require analysis of all packet data in its entirety, packet slicing is a perfect solution to limit the amount of data that an ANIC adapter presents. Examples where this functionality might be relevant is for traffic engineering, billing or protocol analysis type applications. Packets can be optionally sliced to include no packet data at all (only packet headers) or any arbitrary number of bytes, for example just the first 128 bytes of packet data. Different byte slice lengths can be assigned per port or a single value can be applied to all incoming packets.
IP Fragment Handling
Fragmented IP packets are identified and processed as if they were a single IP packet. For example, the fragments will be classified as the same flow and will be steered to the same host packet buffer.