I've got a WAN connection using dynamic IP for which I've configured the OpenDNS servers to be used. These are allocated to the WAN fine, until it finishes negotiating the IP at which point my primary DNS server 208.67.222.222 is overridden by one from Be* 87.194.255.155.

LAN clients are being given the two OpenDNS server IPs though, even if they only join the LAN after the WAN connection has been negotiated and the first OpenDNS server replaced with the Be* server.

So, firstly, why is the DrayTek allowing my preference to be overwritten?

Secondly, why is it handing the OpenDNS server IPs to clients when Force DNS manual setting is unchecked, yet if I don't specify any DNS servers in the WAN dialog it doesn't hand out the IPs of the servers it later collects as part of DHCP but rather itself?