RNRP will override the default ”Automatic metric” enabled setting on the Ethernet adapter belonging to the primary path of lowest RNRP Area in each computer to disabled and the static Interface Metric value ”1” (highest priority). All other interfaces are then set to ”Automatic metric” enabled. The effect is that the primary path of the lowest area will be used for DNS resolution (a valid Primary/Alternate DNS setting on this NIC is of course also required).
As long as your Client Server network area is ”lowest” in number compared to other areas, no action is required. If you for example have Control Area set to 5 and domain controllers on Area 7 you must change a setting in the RNRP Wizard to make 7 your primary area.
Loopback interfaces (IPv4 or IPv6) can be ignored in this regard. Eg 127.0.0.1 (the IPv4 loopback address) is used when client and server happen to be on the same host, this is faster than using the physical Ethernet interface to bounce traffic between two peers sharing the same computer.