The net_cls subsystem tags network packets with a class identifier (classid) that allows the Linux traffic controller (tc) to identify packets originating from a particular control group. The traffic controller can be configured to assign different priorities to packets from different control groups.
- net_cls.classid
net_cls.classid contains a single value in hexadecimal format that indicates a traffic control handle. For example, 0x100001 represents the handle conventionally written as 10:1 in the format used by iproute2.
The format for these handles is: 0xAAAABBBB, where AAAA is the major number in hexadecimal and BBBB is the minor number in hexadecimal. You can omit any leading zeroes; 0x10001 is the same as 0x00010001, and represents 1:1.
Refer to the man page for tc to learn how to configure the traffic controller to use the handles that the net_cls adds to network packets.
