User's Manual

477
PTR A pointer to another part of the domain name space.
SOA Identifies the start of a zone of authority.
 DNS Zone:
In general, the DNS database can dispart into defferent resouce records and each record is called zone. A
zone can include the resource record of all the zones or parts of a zone.A zone is divide into serveral child
zone is to simplize the mangement. After using this distrabuting frame, the administrator can manage every
child zone effectivly when the domain name extends.
 Authoritative name server:
The DNS Server which manages the RR is named authoritative name server.Every server can be an
authoritative name server or many.
 Primary server and slave server:
In order to ensure the high trustiness, DNS requests using many name server to support every zone. The RR
of every zone updates to a primary server manuly or antoly.The primay server can be an authoritative name
server having one or more zone. The other servers(named master DNS server) are standby server servicing
for the same zone,and this can avoiding some instance when the primary server is abnormity.Master servers
make their database are update to date by communicating to primary server. Copying the zone files to many
name servers is named zone exchange.
64.2 DNS Configuration Task List
This modual realize the DNS Resolver only and the DNS Server is not range of this modual.
 Enables DNS-based host name-to-address translation
 Specify the IP address of a domain name server
 Set a default domain name
 Defines a list of domains
 Defines static host name-to-address mapping
 Specify times to retry a DNS query
 Specify timeout waiting for response to a DNS query
 Delete the mapping of a host name to IP address in cache
 Specify the IP address of a primary server
 Enable update function of dynamic DNS
 Set the period of DNS update
 Bind the domain name to a IP address or IP address of interface
 The function of information showing or debug showing
64.3 DNS Configuration Task
64.3.1 Enable
DNS-based host name-to-address translation
That is,make it query the hosts by name or address. This modual enable DNS lookup by default.
In congure use the following command: