H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 252)

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Configuring DNS
Overview
Domain Name System (DNS) is a distributed database used by TCP/IP applications to translate domain
names into corresponding IP addresses. With DNS, you can use simple domain names in some
applications and the DNS server translates them into correct IP addresses.
There are two types of DNS services: static and dynamic. After a user specifies a name, the device checks
the local static name resolution table for an IP address. If no IP address is available, it contacts the DNS
server for dynamic name resolution, which takes more time than static name resolution. Therefore, to
improve efficiency, frequently queried name-to-IP address mappings are stored in the local static name
resolution table.
Static domain name resolution
Static domain name resolution requires you to set up mappings between domain names and IP
addresses manually. IP addresses of the corresponding domain names can be found in the static domain
resolution table when you use applications such as telnet.
Dynamic domain name resolution
Dynamic domain name resolution is implemented by querying the DNS server.
DNS proxy
A DNS proxy forwards DNS requests and replies between DNS clients and a DNS server.
A DNS client considers the DNS proxy as the DNS server and sends a DNS request to the DNS proxy.
The DNS proxy forwards the request to the designated DNS server, and conveys the reply from the DNS
server to the client.
The DNS proxy simplifies network management. When the DNS server address is changed, you only
need to change the configuration on the DNS proxy, instead of on each DNS client.
For more information about DNS, see "
About the H3C Access Controllers Web-Based Configuration
Guide ."