Ok, I can test it again - after we talked yesterday i tried it in both configurations "mq, dns" (with COREDNS_ADDR and coredns ports commented out). that did not work. Then i tried it with public and "mq" with COREDNS_ADDR specified as public IP and UDP/TCP ports specified in docker-compose, which did work. I did not try setting COREDNS_ADDR as the private IP though