Setting UDP data length

Hi team !

I use a WIZ820io module together with Teensy 3.2 module.

I’m able to send UDP packet, but I have a specific need, I would like to send an UDP packet with a bad packet length information. In other words, when I send 4bytes UDP data, I would like the UDP data length header said 3bytes.

Is this possible ?

Thank you for your help.

Best regards.