4. Forwarding
In large, well organized, academic or ISP (Internet Service
Provider) networks you will sometimes find that the network people
have set up a forwarder hierarchy of DNS servers which helps lighten
the internal network load and the load on the outside servers as well.
It's not easy to know if you're inside such a network or not. But by
using the DNS server of your network provider as a ``forwarder'' you
can make the responses to queries faster and less of a load on your
network. This works by your nameserver forwarding queries to your ISP
nameserver. Each time this happens you will dip into the big cache of
your ISPs nameserver, thus speeding your queries up, your nameserver
does not have to do all the work itself. If you use a modem this can
be quite a win. For the sake of this example we assume that your
network provider has two name servers they want you to use, with IP
numbers 10.0.0.1 and 10.1.0.1. Then, in your
named.conf file, inside the opening section called
``options'', insert these lines:
forward first;
forwarders {
10.0.0.1;
10.1.0.1;
};
There is also a nice trick for dialup machines using forwarders, it is described in the qanda section.
Restart your nameserver and test it with dig. Should still
work fine.
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