IPv6 DNS multiple addresses

Been using OpenWRT for some time now however I am having some problems with name name resolution and ipv6 addresses.

The DHCPv6 service is assigning 2 addresses to each machine / device on my network one in a 2a00 public address space and another in a fd84 private space, both addresses are added to DNS and are treated as a round robin address. Is there anyway that I can get DNS on OpenWRT to return the private address or only put the private address into DNS? I have firewall rules on my host which treat the public and private addresses differently e.g. only allowing ssh on the private address.

Any advice would be greatly appreciated.