I've asked the support for it, and there is their response:
Hello Bart,
Currently DNP does not support IPv6. Sure we will add IPv6 support in next releases. However we cannot currently say ETA, but it will be not earlier than IPv6 start really used in Internet.
Best regards,
, Enterprise Solutions engineer.
and after the reply that we are using it and the customers are asking for it:
Hello Bart,
Actually it is first request from real life IPv6 usage. We will definitely increase IPv6 support priority. However at this moment I cannot say ETA.
Best regards,
, Enterprise Solutions engineer.