Resource Records - material

Resource Records:> Within a DNS zone, there are resource records (RR) that provide name resolution.
> DNS Servers are basically database servers that store information about the hosts and subdomain

for which they are responsible in Resource Records.
> When you run your own DNS server, you create a Resource Record for each host name that you

want to be accessible by the rest of the network.
There are several types of Resource Records used by DNS Server:
SOA (Start of Authority): Identifies the name server that is the authoritative source of information

for a DNS domain or zone. It also includes parameters for how long DNS entries should be cached

in a system.
NS (name server): Provides a list of names servers that are assigned to a domain.
A (host address): Provides a name to an address mapping.
AAA (host address): Provides a hostname to an IPv6 address.
PTR: Resolves an address to a name mapping (reverse mapping).
CNAME (canonical name): Creates an alias or alternate DNS domain name for aspecified

hostname. Examples include www.acme.com or ftp.acme.com, which pointto a server on the

acme.com network, such as server01.acme.com. This type of RR isoften used with virtual servers

that point to multiple servers, such as servers that providenetwork load balancing so that work can

be distributed.
SRV (service):Locates servers that are hosting a particular service, including LDAPservers or

domain controllers.
MX (mail exchanger):Identifies which mail exchanger should contact a specifieddomain and in

what order to use each mail host.