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IT Interview Questions:DNS zones
Information Technology (IT) Interview Questions and Answers
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IT Interview Questions:DNS zones
Describe the differences between the 3 types.
DNS stands for Distributed Name System. A DNS server resolves a name to an IP
address, as stated in an earlier answer, but it can also point to multiple IP
addresses for load balancing, or for backup servers if one or more is offline
or not accepting connections. Individual organizations may have their own DNS
servers for their local Intranet. Some sites have their own DNS server to
switch between subdomains within them. For example, a site such as Blogspot
can have subdomains come and go quite frequently. Rather than force every DNS
server to update their own databases whenever someone creates a new blog,
Blogspot could maintain their own DNS server to resolve names within the
blogspot.com domain, e.g., to distinguish between myblog.blogspot.com and
yourblog.blogspot.com ... their DNS server would be queried once blogspot.com
is resolved, and it would be responsible for resolving myblog vs. yourblog. ,
such as the Internet. The following are the three main components of DNS:
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Domain name space and associated resource records (RRs)
A distributed database of name-related information.
DNS Name Servers
Servers that hold the domain name space and RRs, and that
answer queries from DNS clients.
DNS Resolvers
The facility within a DNS
client that contacts DNS name servers and issues name queries to obtain
resource record information.
DNS Zones
A DNS server that has complete information for part of the DNS name space is
said to be the authority for that part of the name space. This authoritative
information is organized into units called zones , which are the main units of
replication in DNS. A zone contains one or more RRs for one or more related
DNS domains. The following are the three DNS zone types implemented in
Windows 2000:
Standard Primary
Holds the master copy of a zone and can
replicate it to secondary zones. All changes to a zone are made on the
standard primary.
Standard Secondary
Contains a read-only copy of zone
information that can provide increased performance and resilience.
Information in a primary zone is replicated to the secondary by use of the
zone transfer mechanism.
Active Directory-integrated
A Microsoft proprietary
zone type, where the zone information is held in the Windows 2000 Active
Directory (AD) and replicated using AD replication.
DNS record types
describe the most important ones. DNS Resource Records
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