D-Link DGS-3324SRi Intelligent Stackable Gigabit Ethernet Switch
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Figure 4- 80. DHCP/BOOTP Relay Settings window
The following fields can be set:
Parameter Description
Interface
The interface name of the IP interface on which the BOOTP or DHCP
servers reside.
Server IP <
0.0.0.0
>
Allows the entry of IP addresses for up to four BOOTP or DHCP servers.
Click
Apply
to set an entry into the
Boot Relay Table
. Entries may be deleted by clicking it’s corresponding
.
DNS Relay
Computer users usually prefer to use text names for computers they may want to open a connection with.
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 subdomain. 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.
Summary of Contents for xStack DGS-3324SRi
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