Dns; Dns Relay - D-Link xstack DES-3810 series Reference Manual

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xStack DES-3810 Series Layer 3 Managed Ethernet Switch Web UI Reference Guide
Figure 10-21 DHCPv6 Relay Settings - View Detail window
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DNS

Computer users usually prefer to use text names for computers for which they may want to open a connection.
Computers themselves, require 32 bit IP addresses. Somewhere, a database of network devices' text names and their
corresponding IP addresses must be maintained.
The Domain Name System (DNS) is used to map names to IP addresses throughout the Internet and has been
adapted for use within intranets. For two DNS servers to communicate across different subnets, the DNS Relay of the
Switch must be used. The DNS servers are identified by IP addresses.
Mapping Domain Names to Addresses
Name-to-address translation is performed by a program called a Name server. The client program is called a Name
resolver. A Name resolver may need to contact several Name servers to translate a name to an address.
The Domain Name System (DNS) servers are organized in a somewhat hierarchical fashion. A single server often
holds names for a single network, which is connected to a root DNS server - usually maintained by an ISP.
Domain Name Resolution
The domain name system can be used by contacting the name servers one at a time, or by asking the domain name
system to do the complete name translation. The client makes a query containing the name, the type of answer
required, and a code specifying whether the domain name system should do the entire name translation, or simply
return the address of the next DNS server if the server receiving the query cannot resolve the name.
When a DNS server receives a query, it checks to see if the name is in its sub domain. If it is, the server translates the
name and appends the answer to the query, and sends it back to the client. If the DNS server cannot translate the
name, it determines what type of name resolution the client requested. A complete translation is called recursive
resolution and requires the server to contact other DNS servers until the name is resolved. Iterative resolution
specifies that if the DNS server cannot supply an answer, it returns the address of the next DNS server the client
should contact.
Each client must be able to contact at least one DNS server, and each DNS server must be able to contact at least
one root server.
The address of the machine that supplies domain name service is often supplied by a DHCP or BOOTP server, or can
be entered manually and configured into the operating system at startup.

DNS Relay

DNS Relay Global Settings
On this page the user can configure the DNS Relay global parameters.
To view the following window, click Network Application > DNS > DNS Relay > DNS Relay Global Settings, as
shown below:
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