Chapter 13: Server services for the LAN LANCOM Reference Manual LCOS 3.50
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Server services for the LAN
Finally, the DNS server checks whether the request to another DNS server
is to be forwarded to another DNS server via a WAN interface (special DNS
forwarding via the DNS destination table).
If the requested name cannot be found in any of the information sources
available to it, the DNS server sends the request to another server—that of
the Internet provider, for example—using the general DNS forwarding mech-
anism, or returns an error message to the requesting computer.
13.2.2 DNS forwarding
If it cannot serve the request from its own DNS tables, the DNS server forwards
the request to other DNS servers. This process is called DNS forwarding.
Here a distinction is made between
special DNS forwarding
Requests for certain name areas are forwarded to certain DNS servers.
general DNS forwarding
All other names not specified in detail are forwarded to the “higher-
level” DNS server.
Special DNS forwarding
With “special DNS forwarding” name areas can be defined for the resolution
of which specified DNS server are addressed.
A typical application for special DNS forwarding results for a home worksta-
tion: The user wants to be able to connect to the company intranet and
directly to the Internet at the same time. The requests sent into the intranet
must be routed to the company DNS server, and all other requests to the DNS
server of the provider.
General DNS forwarding
All DNS requests that cannot be resolved in another way are forwarded to a
DNS server. This DNS server is determined according to the following rules: