Understanding DNS Policy :- Geo Location Based Traffic Management with Primary -Secondary Deployment

Introduction :-

1. In this kind of deployment in an Internet infrastructure you can have multiple number of DNS servers deployed in multiple region across the globe.

Their comes the importance of having a primary & Secondary DNS server in which a company can have 1 Primary DNS server & Multiple Secondary server.

The primary DNS server always have the write zone copy & any updates or modifications will be first committed in the primary zone of the primary server.

On the other hand Secondary DNS server will have and secure read only copy of zone in multiple regions.

The role of Primary -Secondary DNS Server deployment becomes really important in order to implement the Geo- Location based traffic management DNS policy properly.

* For Example :-

There is a company "Magenta info-tech" so it's DNS infrastructure deployment will be like :-

Synchronization :-

Well the Secondary DNS Server will be using some Zone transfer protocol in the likes of Authoritative Transfer ( AXFR) & Incremental Zone Transfer ( IXFR) in order to get an updated Zone copy and spread out the updated copy to multiple Secondary DNS server in the infrastructure which keeps both the servers in a synchronized state.

& If modification or update has been made to the primary zone copy of the Primary DNS Server then below is the diagram which depicts how AXFR & IXFR being a zone transfer protocol will act to maintain proper Synchronization.

Scenario Based Example :-

• Prerequisites :-

In our set up we are having 2 companies

Magenta Info Tech :- is a food delivery company & have a website www.magenta.com

Skyware Cloud solutions :- Is a cloud based company whose main job is web & domain hosting. This company is also hosting www.magenta.com.

Skyware is also having 2 data-centers :-

EU DC :- Located in London

US DC :- Located in Boston

• Project Requirement :-

Since Magenta is a food delivery company so they want a responsive services to be provided to there clients queries with out any delay.

As the main Business revenue of Magenta generates from Europe & USA region so they want clients from these 2 geographical regions should be redirected to the respective closest Data-centers so by which they can quickly access to their resources with a negligible latency.

Hence as per their requirement an European client query should be redirected to EU DC & an USA client query should be redirected to US DC.

So this particular goal can only be achieved if we configure the DNS policy Geo - Location base Traffic Management properly with a Primary - Secondary DNS deployment.

• DNS Policy Deployment :-

Description :-

1. When a European user browses for www.magenta .com the the DNS record is first searched in the Local DNS Server.
2. The local DNS Server will then try to search for the record in Cache reserve. If it doesn't finds any record then it forwards the DNS Query to the secondary server 2 which also act as a name server.
3. The secondary server is updated to the zone copy present in Primary server by the help of Zone transfer protocol ( xfr ) and it finds the record magenta.com.
4. Since we have configured the DNS Policy : Geo - Location based Traffic management in which the DNS Query originating from certain region will be transferred to a specific Data- center.
5. In our scenario the secondary server will give a DNS response with the IP Address of the EU DC i.e. 192.4.2.27
6. The DNS Response will be forwarded by LDNS to the user.
7. Hence the user establishes a connection with EU DC & by this his Traffic is redirected to a specific Data- center for quick response.
8. The same process is also followed for USA based Clients.

• Conclusion :-

In my conclusion I would only like to say that this DNS policy deployment is very effective to manage Business critical traffics in much more efficient way.