If a DNS server receives a request for a domain which he neither serves nor has in cache, then the server has to forward this request to other DNS servers in the Internet. The forwarders should be the nearest ones, normally the DNS servers of ISP. If the forwarders field is empty the DNS still working because the server use the internet gateway to do the DNS search. If in the same network exists a IPBrick.I and a IPBrick.C, the IPBrick.I must have the IPBrick.C eth0 address in the forwarder field. Here you have the most appropriate interface to register the nearest DNS servers (Figure 7.41).
Note: It is now possible to create areas that are of type forward.
Advanced Configurations -> Support service -> DNS