Questions about clone3

[ls760008979]

I want to know the cloned packet with a non empty third parameter.Is the parameter are combined into the cloned packet's payload or somewhere else?

[edgar-costa]

You can get some documentation about clone3 here https://github.com/p4lang/p4c/blob/master/p4include/v1model.p4#L633

The third parameter is a list of the metadata fields you want to preserve.

For example:

p4-learning/examples/l2_learning/p4src/l2_learning_copy_to_cpu.p4

Line 79 in fa91647

clone3(CloneType.I2E, 100, meta);

In this case we copy all fields from the metadata struct.

[ls760008979]

Oh,i may got it,is it means that the third parameter can be preserved and computed only at this switch unless it be added to some head of packet .