Packet classification is one of the key elements of a routers to implement traffic control techniques.
As an example, let us consider an IPv6 packet such as the following one :
What are the fields of the packet that you can match if you want to implement Layer-2 classification ?
TLS record type
Internet protocol version
Hop Limit
Ethernet type
Source port
Source IP address
Ethernet source address
Destination IP address
Destination port
Ethernet destination address
Next header
Traffic class
What are the fields of the packet that you can match if you want to implement Layer-3 classification ?
What are the fields of the packet that you can match if you want to implement Layer-4 classification ?
What are the fields of the packet that you can match if you want to implement application-level (or layer 7) classification ?