In short, a few of the nicer features of your HDA will not be available. You can still point your machines to the DNS server in the HDA and get some of the benefits, like nice URLs for your HDA-provided services. This is not a supported configuration for things like [[Netboot]].
Want to let your HDA handle your DHCP? Here is how to [[Turning_off_DHCP_in_your_router|turn off DHCP in your router]].