Computer Tutorial

Networking Domain Service

DNS is hierarchical in structure. A domain is a subtree of the domain name space. From the root, the assigned top-level
domains in the U.S. are

GOV - Government body.
EDU - Educational body.
INT - International organization
NET - Networks
COM - Commercial entity.
MIL - U. S. Military.
ORG - Any other organization not previously listed.

Outside this list are top level domains for various countries.
Each node on the domain name system is separated by a ".". Example: "mymachine.mycompany.com.". Note that any name
ending in a "." is an absolute domain name since it goes back to root.
DNS Message.

DNS Message format:-

Bits Name Description