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

Describe in brief about tree topology, Tree topology Comments 1 -...

Tree topology Comments 1 - This features star nodes on a bus network 2 - All the disadvantages and advantages of both types of networks described above apply to this s

Program to load the router with the supplied scripts-ccna, Load the Router ...

Load the Router with the Supplied Scripts Enable ! config term ! hostname Router1 ! enable secret class ! no ip domain-lookup !  interface FastEth

Show coaxial cable connectors, Q. Show Coaxial Cable Connectors? - A mo...

Q. Show Coaxial Cable Connectors? - A most common is barrel connector (BNC) - T-connectors are utilized to branch off to secondary cables - Terminators are necessary for

What is a vlan, VLAN - Virtual Local Area Network Vlan is a logical grou...

VLAN - Virtual Local Area Network Vlan is a logical grouping or segmenting a network linked to administratively described ports on a switch, they give Broadcast control, Securit

Summary of osi model, Q. Summary of osi model? - There was no standard ...

Q. Summary of osi model? - There was no standard for networks in the early period and as a result it was difficult for networks to communicate with each other. - The ISO (In

What is silly window syndrome, What is silly window syndrome? It is a d...

What is silly window syndrome? It is a difficulty that can ruin TCP performance. This problem happens when data are passed to the sending TCP entity in large blocks, but an int

Describe a typical dns system, Question: (a) With the help of a diagra...

Question: (a) With the help of a diagram, describe a typical DNS system. (b) Using signal sequence or state transition diagrams, illustrate the following scenarios: i.

Program annotation packages, A fairly renowned approach in this area is Ope...

A fairly renowned approach in this area is OpenMP, a recently developed industry standard for shared memory programming on architectures with uniform memory access characteristics.

Show VLAN membership and configuration, Q. Show VLAN Membership and Configu...

Q. Show VLAN Membership and Configuration? VLAN Membership - May be classified by - Switch port numbers - MAC addresses - IP addresses - IP multicast addresse

Half duplex ethernet operation, Half-Duplex - Capability for data transmis...

Half-Duplex - Capability for data transmission in only single direction at a time among sending station and a receiving station.

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