The dig command is a formidable instrument for troubleshooting queries and responses gained from the Domain Name Service (DNS). It is put in by way of default on many working programs, together with Linux® and Mac OS X. It will also be put in on Microsoft Windows as a part of Cygwin. 

One of the numerous issues dig can do is to accomplish recursive DNS solution and show all the steps that it took for your terminal. This is very helpful for realizing no longer handiest how the DNS works, however for figuring out if there is a matter someplace inside the solution chain that motive solution screw ups on your zones or domain names. 

First, let’s in short overview how a question recursive receives a reaction in a ordinary recursive DNS solution situation: 

1. You because the DNS shopper (or stub resolver) question your recursive resolver for www.instance.com. 
2. Your recursive resolver queries the basis nameserver for NS information for “com.” 
3. The root nameserver refers your recursive resolver to the .com Top-Level Domain (TLD) authoritative nameserver. 
4. Your recursive resolver queries the .com TLD authoritative server for NS information of “example.com.” 
5. The .com TLD authoritative nameserver refers your recursive server to the authoritative servers for instance.com. 
6. Your recursive resolver queries the authoritative nameservers for instance.com for the A document for “www.example.com” and receives 1.2.3.4 as the solution. 
7. Your recursive resolver caches the solution all through the time-to-live (TTL) specified at the document and returns it to you.

The above procedure principally looks as if this:

Step 1

Step 2

Step 3

Step 4

Step 5

This procedure happens each time you sort a URL into your internet browser or fan the flames of your electronic mail shopper. This illustrates why DNS resolution pace and accuracy are so necessary: if the solution is wrong, you could want to repeat this procedure a number of occasions; and if the rate with which you obtain a solution is sluggish, then it’ll make the whole thing you do on-line appear to take longer than it must.  

Driving each DNS resolution pace and accuracy is on the core of the IBM® NS1 Connect® worth proposition.   

Learn extra at IBM NS1 Connect