node.js dns.resolveAny returns an empty array

Question

I'm using dns.resolveAny function to check DNS information about some domains.

One thing I found strange is that for some domains, dns.resolveAny returns an empty array while nslookup command doesn't.

Here's an example:

// node.js version >= 9.2 is required

const dns = require('dns')

dns.resolveAny('www.ifshop.com.tw', (err, ret) => {
  if (err) {
      console.log(`err: ${err}`)
  } else {
      console.log(`ret: ${JSON.stringify(ret)}`)  // JSON.stringify(ret) == [] here
  }
})

resolveAny returns [] . But nslookup successfully returns where www.ifshop.com.tw 's CNAME record.

> nslookup www.ifshop.com.tw
Server:     192.168.1.1
Address:    192.168.1.1#53

Non-authoritative answer:
www.ifshop.com.tw   canonical name = s1759.dname.91app.io.
s1759.dname.91app.io    canonical name = proxy.letssl.91app.io.
proxy.letssl.91app.io   canonical name = proxy-letssl-91app-io-196811564.ap-northeast-1.elb.amazonaws.com.
Name:   proxy-letssl-91app-io-196811564.ap-northeast-1.elb.amazonaws.com
Address: 54.178.248.57
Name:   proxy-letssl-91app-io-196811564.ap-northeast-1.elb.amazonaws.com
Address: 52.196.80.17

Why does this happen?

Is this a bug of resolveAny ?

Or is there a problem in the DNS configuration of www.ifshop.com.tw ?

I also found that dns.resolveCname returns CNAME successfully.

// node.js version >= 9.2 is required

const dns = require('dns')

dns.resolveCname('www.ifshop.com.tw', (err, ret) => {
  if (err) {
      console.log(`err: ${err}`)
  } else {
      console.log(`ret: ${JSON.stringify(ret)}`)
  }
})

Here, JSON.stringify(ret) is equal to ["s1759.dname.91app.io"] .

Answer 1

I set the type of nslookup to any . Then I found the following information.

nslookup
> set type=any
> www.ifshop.com.tw
Server:     10.11.1.5
Address:    10.11.1.5#53

Non-authoritative answer:
www.ifshop.com.tw   hinfo = "ANY obsoleted" "See draft-ietf-dnsop-refuse-any"

Authoritative answers can be found from:

From the information above, we can infer that the DNS provider refuse to respond to the queries of any type.