Iterative query

[SkySai1]

Hello, how can i send iterative query to find NS records from 3rd lvl DNS?
So, i need to find NS records from mail.google.com, if i type this:

import dns.resolver

result = dns.resolver.resolve('mail.google.com', 'A')
for ipval in result:
    print('IP', ipval.to_text());

I get this:

IP 173.194.73.17
IP 173.194.73.18
IP 173.194.73.19
IP 173.194.73.83

But, if i type this:

print("Hello World")
result = dns.resolver.resolve('mail.google.com', 'NS' )
for ipval in result:
    print('IP', ipval.to_text());

I get this:
dns.resolver.NoAnswer: The DNS response does not contain an answer to the question: mail.google.com. IN NS

I think dnsresolver send recursive question which not supported on the google's DNS.

[sebix]

But, if i type this:

print("Hello World")
result = dns.resolver.resolve('mail.google.com', 'NS' )
for ipval in result:
    print('IP', ipval.to_text());

I get this: dns.resolver.NoAnswer: The DNS response does not contain an answer to the question: mail.google.com. IN NS

I think dnsresolver send recursive question which not supported on the google's DNS.

You are asking for a DNS entry which does not exist. Maybe you actually want to query NS of google.com and then send a query to that resulting nameserver.

[SkySai1]

Okay, i choose wrong example.
How about docs.microsoft.com.

import dns.resolver

print("Hello, World!")
result = dns.resolver.query('docs.microsoft.com', 'NS')
for address in result:
    print("IP", address.to_text())

I, got this:
dns.resolver.NoAnswer: The DNS response does not contain an answer to the question: docs.microsoft.com. IN NS

And what i get when looking NS records from DIG:

;; AUTHORITY SECTION:
dscb.akamaiedge.net.	1000	IN	SOA	n0dscb.akamaiedge.net. hostmaster.akamai.com. 1642607037 1000 1000 1000 1800

How it can be?

[sebix]

What you are showing is the SOA entry of docs.microsoft.com, not the NS record

[rthalley]

dns.resolver.query() is not like "dig", it is just giving you the answer to your question. In this case, the answer is the NoAnswer exception because you're looking for something which does not exist. "dig" is showing you the whole DNS message, which may contain other information, for example the SOA record.

We might be able to help you better if you could say more about what you are trying to do. Are you perhaps trying to find which nameservers are authoritative for "docs.microsoft.com" (or whatever)?

Also, even if a NS query succeeds, your code is not going to work because you're treating the NS records as if they were addresses. They are names.