3com 8807 사용자 가이드
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DNS C
ONFIGURATION
Introduction to DNS
Used in the TCP/IP application, Domain Name System (DNS) is a distributed
database which provides the translation between domain name and the IP
address. In this way, the user can use domain names that are easy to memorize
and meaningful, and never needs to keep obscure IP addresses in mind.
database which provides the translation between domain name and the IP
address. In this way, the user can use domain names that are easy to memorize
and meaningful, and never needs to keep obscure IP addresses in mind.
There are two kinds of domain name resolutions: static domain name resolution
and dynamic domain name resolution, which supplement each other in real
application. On resolving a domain name, use the static resolution first. If it fails,
use the dynamic resolution method. You can put some common domain names
into the static domain name resolution table to raise the domain name resolution
efficiency greatly.
and dynamic domain name resolution, which supplement each other in real
application. On resolving a domain name, use the static resolution first. If it fails,
use the dynamic resolution method. You can put some common domain names
into the static domain name resolution table to raise the domain name resolution
efficiency greatly.
Static Domain Name
Resolution
Static domain resolution is to establish maps between domain name and the IP
address manually. When you perform some applications using domain names, the
system can obtain the IP address of the specified domain name by searching the
static domain name resolution table.
address manually. When you perform some applications using domain names, the
system can obtain the IP address of the specified domain name by searching the
static domain name resolution table.
Dynamic Domain Name
Resolution
Dynamic domain name resolution is implemented by inquiring the domain name
server. As a DNS client, the switch sends an inquiry request to the domain name
server, and the domain name server searches the related IP address of the domain
name in its own database and sends it back to the switch. If the domain name
server judges that the domain name does not belong to the local domain, it
forwards the request to the upper level domain name resolution server till the
resolution is finished.
server. As a DNS client, the switch sends an inquiry request to the domain name
server, and the domain name server searches the related IP address of the domain
name in its own database and sends it back to the switch. If the domain name
server judges that the domain name does not belong to the local domain, it
forwards the request to the upper level domain name resolution server till the
resolution is finished.
Dynamic domain name resolution supports the buffer function. It stores each
successful domain name/IP address mapping that is resolved dynamically in the
dynamic domain name buffer. When the same domain name is searched next
time, it can be read directly from the buffer, without requesting the domain name
server. The aged mapping in the buffer is deleted after a certain period of time to
ensure the updated contents can be got from the domain name server timely. The
aging time is set by the domain name server and obtained by the switch from the
protocol packet.
successful domain name/IP address mapping that is resolved dynamically in the
dynamic domain name buffer. When the same domain name is searched next
time, it can be read directly from the buffer, without requesting the domain name
server. The aged mapping in the buffer is deleted after a certain period of time to
ensure the updated contents can be got from the domain name server timely. The
aging time is set by the domain name server and obtained by the switch from the
protocol packet.
Dynamic domain name resolution supports the domain name suffix list function.
You can set some domain name suffixes beforehand and input part of the domain
name field during the domain name resolution, then the system adds different
suffixes to the input domain name automatically for resolution. For example, if a
user wants to search the domain name "3Com.com", he can configure the
"com" in the suffix list and input "3Com". Then the system connects the input
domain name with the suffix into "3Com.com" automatically to search. When the
domain name suffix is used, if the input domain name does not include ".", like
You can set some domain name suffixes beforehand and input part of the domain
name field during the domain name resolution, then the system adds different
suffixes to the input domain name automatically for resolution. For example, if a
user wants to search the domain name "3Com.com", he can configure the
"com" in the suffix list and input "3Com". Then the system connects the input
domain name with the suffix into "3Com.com" automatically to search. When the
domain name suffix is used, if the input domain name does not include ".", like