Monday, August 24, 2015

DNS or Bind in Linux -1

DNS Domain Name System is a hierarchical  distributed naming system for computers services, or any resource connected to the internet or private network. Mostly, It associates information from domain names with the IP addresses. Also Domain name systems are used for obtaining email servers in a specific domain.
Domain Name Space:
A domain name space consists of a tree of domain names. Each node in the tree has  zero or more resoruce records associated with this domain name. The tree sub-divides into zones beginning at the root zone.
DNS root zone is the top-level DNS zone in the hierachical namespace of the DNS of the itnernet. The root zone is managed by the IANA and ICANN.
NS records are the DNS servers ( or name servers) records  for a zone.
Root zone is “.” is the root of the DNS tree on the internet. It is the zone that contains the zones: com, net,gov, org, in, nl….
The root name servers are the DNS servers that are authoritative for the root zone.
DNS Records:
DNS servers are used to resolve name to IP addresses. We have different types of records that can be resolved:
A record is the record for a host name and it can be used to resolve the IP address from the name
NS record is a record for a domain name and it can be used to get the list of DNS servers that are authoritiative for this domain.
MX is a record for the email servers of a specific domain name, it maps your domain name to one or more of FQDN of email servers.  These records will have different metrics. The one with the lowest metric is the best

Follow us in our next Blog for more about DNS.
I hope this was helpful, and I would like to thank you for reading

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