Running dnsx

Learn about running dnsx with examples including commands and output

For all of the flags and options available for dnsx be sure to check out the Usage page. On this page we share examples running ‘dnsx’ with specific flags and goals and the output you can expect from each.

If you have questions, reach out to us through Help.

Basic Examples

DNS Resolving

Filter active hostnames from the list of passive subdomains, obtained from various sources:

subfinder -silent -d hackerone.com | dnsx -silent

a.ns.hackerone.com
www.hackerone.com
api.hackerone.com
docs.hackerone.com
mta-sts.managed.hackerone.com
mta-sts.hackerone.com
resources.hackerone.com
b.ns.hackerone.com
mta-sts.forwarding.hackerone.com
events.hackerone.com
support.hackerone.com

Print A records for the given list of subdomains:

subfinder -silent -d hackerone.com | dnsx -silent -a -resp

www.hackerone.com [104.16.100.52]
www.hackerone.com [104.16.99.52]
hackerone.com [104.16.99.52]
hackerone.com [104.16.100.52]
api.hackerone.com [104.16.99.52]
api.hackerone.com [104.16.100.52]
mta-sts.forwarding.hackerone.com [185.199.108.153]
mta-sts.forwarding.hackerone.com [185.199.109.153]
mta-sts.forwarding.hackerone.com [185.199.110.153]
mta-sts.forwarding.hackerone.com [185.199.111.153]
a.ns.hackerone.com [162.159.0.31]
resources.hackerone.com [52.60.160.16]
resources.hackerone.com [3.98.63.202]
resources.hackerone.com [52.60.165.183]
resources.hackerone.com [read.uberflip.com]
mta-sts.hackerone.com [185.199.110.153]
mta-sts.hackerone.com [185.199.111.153]
mta-sts.hackerone.com [185.199.109.153]
mta-sts.hackerone.com [185.199.108.153]
gslink.hackerone.com [13.35.210.17]
gslink.hackerone.com [13.35.210.38]
gslink.hackerone.com [13.35.210.83]
gslink.hackerone.com [13.35.210.19]
b.ns.hackerone.com [162.159.1.31]
docs.hackerone.com [185.199.109.153]
docs.hackerone.com [185.199.110.153]
docs.hackerone.com [185.199.111.153]
docs.hackerone.com [185.199.108.153]
support.hackerone.com [104.16.51.111]
support.hackerone.com [104.16.53.111]
mta-sts.managed.hackerone.com [185.199.108.153]
mta-sts.managed.hackerone.com [185.199.109.153]
mta-sts.managed.hackerone.com [185.199.110.153]
mta-sts.managed.hackerone.com [185.199.111.153]

Extract A records for the given list of subdomains:

subfinder -silent -d hackerone.com | dnsx -silent -a -resp-only

104.16.99.52
104.16.100.52
162.159.1.31
104.16.99.52
104.16.100.52
185.199.110.153
185.199.111.153
185.199.108.153
185.199.109.153
104.16.99.52
104.16.100.52
104.16.51.111
104.16.53.111
185.199.108.153
185.199.111.153
185.199.110.153
185.199.111.153

Extract CNAME records for the given list of subdomains:

subfinder -silent -d hackerone.com | dnsx -silent -cname -resp

support.hackerone.com [hackerone.zendesk.com]
resources.hackerone.com [read.uberflip.com]
mta-sts.hackerone.com [hacker0x01.github.io]
mta-sts.forwarding.hackerone.com [hacker0x01.github.io]
events.hackerone.com [whitelabel.bigmarker.com]

Extract ASN records for the given list of subdomains:

subfinder -silent -d hackerone.com | dnsx -silent  -asn

b.ns.hackerone.com [AS13335, CLOUDFLARENET, US]
a.ns.hackerone.com [AS13335, CLOUDFLARENET, US]
hackerone.com [AS13335, CLOUDFLARENET, US]
www.hackerone.com [AS13335, CLOUDFLARENET, US]
api.hackerone.com [AS13335, CLOUDFLARENET, US]
support.hackerone.com [AS13335, CLOUDFLARENET, US]

Probe using dns status code on given list of (sub)domains:

subfinder -silent -d hackerone.com | dnsx -silent -rcode noerror,servfail,refused

ns.hackerone.com [NOERROR]
a.ns.hackerone.com [NOERROR]
b.ns.hackerone.com [NOERROR]
support.hackerone.com [NOERROR]
resources.hackerone.com [NOERROR]
mta-sts.hackerone.com [NOERROR]
www.hackerone.com [NOERROR]
mta-sts.forwarding.hackerone.com [NOERROR]
docs.hackerone.com [NOERROR]

Extract subdomains from given network range using PTR query:

echo 173.0.84.0/24 | dnsx -silent -resp-only -ptr

cors.api.paypal.com
trinityadminauth.paypal.com
cld-edge-origin-api.paypal.com
appmanagement.paypal.com
svcs.paypal.com
trinitypie-serv.paypal.com
ppn.paypal.com
pointofsale-new.paypal.com
pointofsale.paypal.com
slc-a-origin-pointofsale.paypal.com
fpdbs.paypal.com

Extract subdomains from given ASN using PTR query:

echo AS17012 | dnsx -silent -resp-only -ptr 

apiagw-a.paypal.com
notify.paypal.com
adnormserv-slc-a.paypal.com
a.sandbox.paypal.com
apps2.paypal-labs.com
pilot-payflowpro.paypal.com
www.paypallabs.com
paypal-portal.com
micropayments.paypal-labs.com
minicart.paypal-labs.com

---

DNS Bruteforce

Bruteforce subdomains for given domain or list of domains using d and w flag:

dnsx -silent -d facebook.com -w dns_worldlist.txt

blog.facebook.com
booking.facebook.com
api.facebook.com
analytics.facebook.com
beta.facebook.com
apollo.facebook.com
ads.facebook.com
box.facebook.com
alpha.facebook.com
apps.facebook.com
connect.facebook.com
c.facebook.com
careers.facebook.com
code.facebook.com

Bruteforce targeted subdomain using single or multiple keyword input, as d or w flag supports file or comma separated keyword inputs:

dnsx -silent -d domains.txt -w jira,grafana,jenkins

grafana.1688.com
grafana.8x8.vc
grafana.airmap.com
grafana.aerius.nl
jenkins.1688.com
jenkins.airbnb.app
jenkins.airmap.com
jenkins.ahn.nl
jenkins.achmea.nl
jira.amocrm.com
jira.amexgbt.com
jira.amitree.com
jira.arrival.com
jira.atlassian.net
jira.atlassian.com

Values are accepted from stdin for all the input types (-list, -domain, -wordlist). The -list flag defaults to stdin, but the same can be achieved for other input types by adding a - (dash) as parameter:

cat domains.txt | dnsx -silent -w jira,grafana,jenkins -d -

grafana.1688.com
grafana.8x8.vc
grafana.airmap.com
grafana.aerius.nl
jenkins.1688.com
jenkins.airbnb.app
jenkins.airmap.com
jenkins.ahn.nl
jenkins.achmea.nl
jira.amocrm.com
jira.amexgbt.com
jira.amitree.com
jira.arrival.com
jira.atlassian.net
jira.atlassian.com

DNS Bruteforce with Placeholder based wordlist

$ cat tld.txt

com
by
de
be
al
bi
cg
dj
bs

dnsx -d google.FUZZ -w tld.txt -resp

      _             __  __
   __| | _ __   ___ \ \/ /
  / _' || '_ \ / __| \  / 
 | (_| || | | |\__ \ /  \ 
  \__,_||_| |_||___//_/\_\ v1.1.2

      projectdiscovery.io

google.de [142.250.194.99] 
google.com [142.250.76.206] 
google.be [172.217.27.163] 
google.bs [142.251.42.35] 
google.bi [216.58.196.67] 
google.al [216.58.196.68] 
google.by [142.250.195.4] 
google.cg [142.250.183.131] 
google.dj [142.250.192.3] 

Wildcard filtering

A special feature of dnsx is its ability to handle multi-level DNS based wildcards, and do it so with a very reduced number of DNS requests. Sometimes all the subdomains will resolve, which leads to lots of garbage in the output. The way dnsx handles this is by keeping track of how many subdomains point to an IP and if the count of the subdomains increase beyond a certain threshold, it will check for wildcards on all the levels of the hosts for that IP iteratively.

dnsx -l subdomain_list.txt -wd airbnb.com -o output.txt

---

Dnsx as a library

It’s possible to use the library directly in your golang programs. The following code snippets is an example of use in golang programs. Please refer to here for detailed package configuration and usage.

package main

import (
	"fmt"

	"github.com/projectdiscovery/dnsx/libs/dnsx"
)

func main() {
	// Create DNS Resolver with default options
	dnsClient, err := dnsx.New(dnsx.DefaultOptions)
	if err != nil {
		fmt.Printf("err: %v\n", err)
		return
	}

	// DNS A question and returns corresponding IPs
	result, err := dnsClient.Lookup("hackerone.com")
	if err != nil {
		fmt.Printf("err: %v\n", err)
		return
	}
	for idx, msg := range result {
		fmt.Printf("%d: %s\n", idx+1, msg)
	}

	// Query
	rawResp, err := dnsClient.QueryOne("hackerone.com")
	if err != nil {
		fmt.Printf("err: %v\n", err)
		return
	}
	fmt.Printf("rawResp: %v\n", rawResp)

	jsonStr, err := rawResp.JSON()
	if err != nil {
		fmt.Printf("err: %v\n", err)
		return
	}
	fmt.Println(jsonStr)

	return
}