Dns records and messages - application layer, Computer Networking

Assignment Help:

DNS Records  and Messages

Two types  of records  are used DNS. The  question records  are used in the question  section of the query and response  messages. The resource  records  are used in the  answer  authoritative  and additional  information sections of the  response  message.

Question Record: A questions records in used by the client  to get  information  from a server. This contains the domain  name.

Resource Record: Each domain  name is  associated  with a  record  called  the resource  record. The server database  consists  or resource  returned by the server to the client.

A resource  records is a quadruple that contains the  following  fields.

Name , Value , Type , TTL

TTL  is the time  to live of  the resource records. It determines  when a resource  should be  removed  from a cache form a  cache. In the example  records given below  we ignore the TTL  field.

The  meaning of  name  and value  depend on  type:

If a DNS  server is authoritative for a  particular host name  then the DNS  server will  contain  a type a record for the  hostname. If a server is not authoritative  for a hostname  then the  server will contain a type NS record for the  domain  that includes the hostname. It  will also  contain  a Type  a record that provides the IP address of the DNS  server in the value field of the NS  records. As an example suppose an edu TLD server is not  authoritative for the host gain cs un mass edu. Then this server will contains  a record for a  domain that includes the host cs mass. Edu. For example  ( umass edu dns unmass. Edu  NS) the du TLD server would  also contain a Type a record which maps the DNS. Server dns  umass.edu to an IP address for example  ( dns umass edu 128.119.111A)


Related Discussions:- Dns records and messages - application layer

Determine about the security systems, Determine about the Security Systems ...

Determine about the Security Systems If the company intends to connect to the Internet, then it should pay great attention to the configuration of firewalls. Just as no one wo

Describe the tcp/ip reference model, Computer Networks 1. Differentiate...

Computer Networks 1. Differentiate WAN and LAN. 2. Describe the TCP/IP Reference Model with diagram. 3. Explain Circuit switching and message switching. 4. List the fu

Explain the changes to the ip stack, After powering up his PC, Bob notices ...

After powering up his PC, Bob notices the PC was not able to properly connect to network devices. He obtained the following information from his workstation: C:\>ipconfig Win

Private network, Single company or organization owns this. They are usually...

Single company or organization owns this. They are usually LAN technologies. There can be multiple LANs in a campus or building linked together. They are sometimes known Intranet.

Describe networking, Describe networking. Networking refers to the inte...

Describe networking. Networking refers to the inter connection among computers and peripherals for data communication. Networking can be done using wired cabling or by wireless

What is unacknowledged connectionless service, What is Unacknowledged conne...

What is Unacknowledged connectionless service This service is a datagram-style service. It is a very simple service that does not involve any of the flow- and error-control mec

How firewall configuration makes all the difference, How Firewall configura...

How Firewall configuration makes all the difference The greatest blunder that any company make is to just install a firewall and think that they have ensured perfect securit

packing -unpacking data with parallel virtual machine , Packing and Unpack...

Packing and Unpacking Data pvm_packs - Pack the active message buffer with arrays of prescribed data type: int info = pvm_packf( const char *fmt, ... ) int info = pv

What is internet, I have a project on Information Communication Technology(...

I have a project on Information Communication Technology(I.C.T). So sir I want to know that what is internet? and how it works?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd