H3C Technologies H3C MSR 50 - Manual (Page 219)

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Configuring DNS
Overview
Domain Name System (DNS) is a distributed database that provides TCP/IP applications with the
mappings between host names and IP addresses. With DNS, you can use easy-to-remember host names
in some applications and let the DNS server translate them into correct IP addresses.
For more information about DNS, see Layer 3—IP Services Configuration Guide in H3C MSR Series
Routers Configuration Guide (V5).
DNS provides the following functions:
• Dynamic domain name resolution—Implemented by querying the DNS server.
• DNS proxy—Forwards DNS requests and replies between the DNS client and DNS server.
Recommended configuration procedure
Configuring dynamic domain name resolution
Task Remarks
Enabling dynamic domain name resolution
Required.
Enable dynamic domain name resolution.
Disabled by default.
Specifying a DNS server
Required.
Not specified by default.
You can specify up to six DNS servers.
Configuring a domain name suffix
Optional.
A suffix is used when the name to be resolved is incomplete. The
system can supply the missing part. For example, a user can
configure com as the suffix for aabbcc.com. The user only needs
to enter aabbcc to obtain the IP address of aabbcc.com because
the system adds the suffix and delimiter before passing the name
to the DNS server.
Not configured by default.
You can configure up to ten DNS suffixes.
Clearing the dynamic domain name cache
Optional.
Clear the dynamic IPv4 domain name cache.
The DNS client stores latest mappings between domain names
and IP addresses in the dynamic domain name cache. The DNS
client searches the cache for a repeated query rather than sends
a request to the DNS server. The mappings are aged out from the
cache after a certain time. You can also manually clear the
cache.