All about DNS


.nl stats and data - SIDN LabsAPNIC Labs StatsCZ.NIC StatisticsCensysCheck Propagation of DNS RecordsCloudflare RadarCollection of "bad" packets in PCAPsCompacted-DNS (C-DNS): A Format for DNS Packet CaptureCurated Lists of DNS Server SoftwareCyber Threat Intelligence FeedsDMAP Domain Mapper by SIDN LabsDNS Authoritative Server BenchmarksDNS Census 2013DNS CoffeeDNS Core CensusDNS Privacy ProjectDNS Quality/Overview ToolsDNS Queries to Authoritative DNS Server at SURFnet by Google's Public DNS ResolverDNS Replay Tool (drool)DNS Test Names & Resource RecordsDNS ToysDNS open zone dataDNSCAPDNSDBDNSMONDNSSEC Deployment MapsDNSSEC Deployment ReportsDNSSEC Early Warning SystemDNSTOPDiG GUI: DiG Web InterfaceDomain Crawling ListsDomain Name System (DNS) ParametersFlamethrowerForward DNS Rapid7Get your public IP using DNSHello DNSICANN Indentifier Technologies Health IndicatorsICANN Managed Root Servers StatisticsIP Flow Information Export (IPFIX) EntitiesInternet Maps (RIPE NCC)List of DNS related RFCsLists of DNS BlocklistsMajor DNSSEC Outages and Validation FailuresMeasurement Factory: DNS SurveyNextDNSOWASP AmassOpen INTELPacketQ: Query PCAPs using SQLPassive DNS (CIRCL)Passive DNS – Common Output FormatPi-hole: Network-wide Ad BlockingPublic DNS Server ListPublic Suffix ListRIPE AtlasRIPEstat: Providing open data and insights for Internet resourcesRSSAC002 DNS Root Server DataRelationship between DNS RFCsResolver TestbedRoot ServersRouting Information Service (RIS)SIDN Labs DNS WorkbenchShadowserver DashboardShadowserver Scanning ProjectShodanSubdomain Enumeration by Bastian KanbachTLD Apex HistoryWildcard DNS for IP AddressesZMap ProjectZonefiles: Domain ListsZonemaster : Run domain Run domain testaddr.toolsdnsdumpsterdnskv: DNS-based Key-Value Storagednsperf and resperfdnsteal DNS Exfiltration Tooldnsthoughtiodine DNS DNS-based Key-Value Storemess with dnsrespdiff

.nl stats and data - SIDN Labs

DNS | DNSSEC | Dataset | IP | Network

Historic datasets (from 2014 onwards) for the .nl TLD. Datasets are available in JSON format.

Datasets cover information about:

  • DNS
    • Domain Names
    • Query Type
    • Response Codes
    • IPv6 Support
  • Resolvers
    • Location
    • Number of IP addresses
    • Validating Resolvers
    • Popular Networks
    • Port Randomness
    • Validating Queries
    • DANE
    • Used Algorithms
  • Mail
    • Mail Resource Records (RRs)
    • SPF Information

APNIC Labs Stats

Autonomous System | BGP | DNS | DNSSEC | Dataset | IP

APNIC gathers many statistics and offers them on their website. However, they provide way more data than it might initially look like, since many of the datasets are not linked from their main page.

CZ.NIC Statistics

DNS | Dataset

The website contains information about the cz. TLD operated by CZ.NIC. It contains information about the query volume, query type, round-trip time (RTT) and geographic location of the traffic sources. It also has information about the registry functions, such as registrar information, domain transfers or whois requests. Lastly, information about the mojeID accounts, a login provider operated by CZ.NIC is also available.


Certificate | DNS | Dataset | IP | Network

Censys performs regular scans for common protocols (e.g., DNS, HTTP(S), SSH). Provides a search for TLS certificates.

Access is free, but requires registration. The website no longer provides free bulk access. Bulk access requires a commercial or a research license. The free access is limited to 1000 API calls per day.

    author = {Zakir Durumeric and David Adrian and Ariana Mirian and Michael Bailey and J. Alex Halderman},
    title = {A Search Engine Backed by {I}nternet-Wide Scanning},
    booktitle = {Proceedings of the 22nd {ACM} Conference on Computer and Communications Security},
    month = oct,
    year = 2015

Cloudflare Radar

BGP | DDoS | DNS | Dataset | IP | Network

Cloudflare Radar is Cloudflare's reporting website about internet trends and general traffic statistics. The website shows information about observed attacks and attack types and links to the DDoS report. General traffic statistics are reported, such as the used browser, fraction of human traffic, IP, HTTP, and TLS version.

The website also provides more detailed information on domains and IP addresses. Domains have information about age, popularity, and visitors. IP addresses have ASN and geolocation information.

More information about Cloudflare Radar is available in the introduction blog post.

The Radar data is also available via API, for example the attack data:

DNS Coffee

DNS | Dataset | IP | Network | Search

DNS Coffee collects and archives stats from DNS Zone files in order to provide insights into the growth and changes in DNS over time.

The website includes information such as the size of different zones. It tracks over 1200 zone files.

It provides searching through the zones files based on domain names, name servers, or IP addresses. It can also visualize the relationship between a domain, the parent zones and the name server in what they call a "Trust Tree".

DNS Core Census

DNS | Dataset | IP | Network

The DNS Core Census is an ICANN project to gather information about top-level-domains (TLDs). This covers ccTLDs, gTLDs, effective TLDs (like, and entries in arpa. The census contains information about the zone, like metadata and contractual information, about the name servers, about addresses of the name servers, and the route origins. The data is kept for a 35-day rolling window.

Further information about the project can be found in this presentation and OCTO-019 from ICANN's Chief Technology Officer

DNS Quality/Overview Tools

DNS | DNSSEC | Dataset | Network | Tool

Check My DNS

Browser-based DNS resolver quality measurement tool. Uses the browser to generate many resolver queries and tests for features they should have, such as EDNS support, IPv6, QNAME Minimization, etc.

This test is also available as a CLI tool:

DNSSEC Debugger

Analyze DNSSEC deployment for a zone and show errors in the configuration.


Gives an overview of DNSSEC delegations, response sizes, and name servers.



The website has an online test, which performs DNS lookups. These DNS lookups test if certain resource records are overwritten in the cache. The tool can then determine what DNS software is used, where the server is located, how many caches there are, etc.

EDNS Compliance Tester

Test name server of zones for correct EDNS support.

The Transitive Trust and DNS Dependency Graph Portal

Shows the trust dependencies in DNS. Given a domain name, it can show how zones delegate to each other and why. The delegation is done between IP addresses and zones.

Root Canary Project

The project used to monitor the first root KSK key rollover. Now it contains the paper "Roll, Roll, Roll your Root: A Comprehensive Analysis of the First Ever DNSSEC Root KSK Rollover" describing the experiences of the first root KSK rollover

Additionally, it includes a tester for DNSSEC algorithm support, which shows the algorithms supported by the currently used recursive resolver. It provides statistics about support for DNSSEC algorithms. It has a web-based test to test your own resolver and provides a live monitoring using the RIPE Atlas.

DNSSEC algorithms resolver test

DNS Queries to Authoritative DNS Server at SURFnet by Google's Public DNS Resolver

DNS | Dataset | Network

This dataset covers approximately 3.5 billion DNS queries that were received at one of SURFnet's authoritative DNS servers from Google's Public DNS Resolver. The queries were collected during 2.5 years. The dataset contains only those queries that contained an EDNS Client Subnet.

The dataset covers data from 2015-06 through 2018-01.

DOI Identifier

DNS Test Names & Resource Records


The zone hosts many weird DNS records which are helpful in testing and configurations and see how they handle these entries.

Some examples of hosted entries:

  • with a TTL of 0 seconds
  • a CNAME loop of length 2
  • with 64 A records
  • with a wide mix of record types for ANY queries
  • for long domains and labels
  • áàăâåäãąąāæćĉčċçďđéèĕêěëėęēğĝġģ to test umlauts
  • Domains for SRV, HINFO, CAA, LOC, TLSA, SSHFP, and OPENPGPKEY records

DNS Toys

DNS | Tool

DNS Toys is an authoritative DNS server offering different unit conversion and lookup tools.

Some examples from the website include:

# Lookup time by city name
dig newyork.time

# or weather

# Return the client IP address
dig ip

# Number conversion from decimal to hex
dig 100dec-hex.base


DNS | Dataset | Network

Historical DNS database. Contains information recorded at recursive resolver about domain names, first/last seen, current bailiwick. Allows to see the lifetime of resource records and can be used as a large database.

Domain Crawling Lists

DNS | Dataset

Domain popularity lists provide a starting point for crawling domains with the most users. The most commonly used list for security research is the Alexa list.

  • Alexa
    The list is updated daily and contains one million websites. The ranking is based on page views, but very volatile.
  • CISCO Umbrella
    The list is updated daily and contains one million websites. The ranking is based on traffic seen on the OpenDNS resolvers.
  • Majestic
    The list is updated daily and contains one million websites. The ranking is based on backlinks from other websites.
  • Tranco
    A Research-Oriented Top Sites Ranking Hardened Against Manipulation
    The Tranco list aims to provide a better list for security research. The authors explain on their website and their paper what the flaws in the existing lists.
  • Quantcast
    The list is updated daily and contains around 500,000 websites. It is based on users visiting the site within the previous month and highly US focussed.
  • Cloudflare Radar Cloudflare uses their DNS resolver to create a top 1 million list. The lists are also available on a per country level, e.g., More details are available in their announcement blog post.
  • CrUX Chrome Google Chrome collects the top 1 million visited website and published them as part of the Chrome UX Report. The repository captures the monthly data and provides access to older versions. In an Internet Measurement Conference (IMC) paper this list was shown to best correlate with the HTTP requests as seen by Cloudflare.

Forward DNS Rapid7

DNS | Dataset | IP | Network

This dataset contains the responses to DNS requests for all forward DNS names known by Rapid7's Project Sonar. Until early November 2017, all of these were for the 'ANY' record with a fallback A and AAAA request if necessary. After that, the ANY study represents only the responses to ANY requests, and dedicated studies were created for the A, AAAA, CNAME and TXT record lookups with appropriately named files.

The data is updated every month. Historic data can be downloaded after creating a free account.

Get your public IP using DNS


Some Open DNS operators provide a way to return the IP address of the request packet.

Google DNS:

dig txt +short


dig +short


$ dig +short TXT
"ns" "2001:db8::abcd"
"ecs" ""
"ip" "" 

The ds stands for dual stack. It is also reachable under to force IPv6 or to force IPv4.

ns stands for the unicast IP address of the recursive resolver. ecs contains the EDNS client subnet information if the resolver uses the option. In this case, ip contains a representative IP within the ECS, not necessarily the IP of the client.

The new version is introduced in this blog post

The old version might be decommissioned:

dig +short

$ curl

$ curl

$ curl

$ curl


ICANN Indentifier Technologies Health Indicators

DNS | DNSSEC | Dataset | Network

ICANN tracks the general health of the DNS ecosystem and related ecosystems. The data is updated irregularly, but historic data is available. The collected data covers eight major topics:

  1. M1: inaccuracy of Whois Data
  2. M2: Domain Name Abuse
  3. M3: DNS Root Traffic Analysis
  4. M4: DNS Recursive Server Analysis
  5. M5: Recursive Resolver Integrity
  6. M6: IANA registries for DNS parameters
  7. M7: DNSSEC Deployment.
  8. M8: DNS Authoritative Servers Analysis

Each topic has too many sub categories to list here.

Lists of DNS Blocklists

DNS | Dataset | IP | Network | Spam | Tool

These projects either operate DNS based Real-time Blackhole Lists (RBL) or allow checking if an IP is contained. The Multi-RBL websites are helpful in finding a large quantity of RBLs.


DNS | Tool

A free and configurable DNS resolver. It provides customizable blocking, such as for ads, trackers, or malicious websites. Additionally, statistics can be shown, such as for most blocked websites.

A similar self-hosted variant is Pi-hole.


CTF | DNS | Tool

The OWASP Amass tool suite obtains subdomain names by scraping data sources, recursive brute forcing, crawling web archives, permuting/altering names and reverse DNS sweeping. Additionally, Amass uses the IP addresses obtained during resolution to discover associated net blocks and ASNs. All the information is then used to build maps of the target networks.


DNS | Dataset | IP | Network

Open INTEL is an active DNS database. It gathers information from public zone files, domain lists (Alexa, Umbrella), and reverse DNS entries. Once every 24 hours, data is collected about a bunch of DNS RRsets (SOA, NS, A, AAAA, MX, TXT, DNSKEY, DS, NSEC3, CAA, CDS, CDNSKEY). The data is openly available as AVRO files and dates back until 2016.

The data can be freely downloaded. There is documentation on the layout of the AVRO files.

The project is similar to Active DNS but seems to be larger in scope.

Pi-hole: Network-wide Ad Blocking

DNS | Tool

A free and configurable DNS stub-resolver. It provides customizable blocking, such as for ads, trackers, or malicious websites. Additionally, statistics can be shown, such as for the most blocked website.

It can also function as a DHCP server for clients on the same network.

A similar service is NextDNS.

RIPEstat: Providing open data and insights for Internet resources

Autonomous System | BGP | DNS | Dataset | Network | Tool

RIPEstat is a network statistics platform by RIPE. The platform shows data for IP addresses, networks, ASNs, and DNS names. This includes information such as the registration information, abuse contacts, blocklist status, BGP information, geolocation lookups, or reverse DNS names. Additionally, the website links to many other useful tools, such as an address space hierarchy viewer, historical whois information, and routing consistency checks.

Resolver Testbed

DNS | Tool

This repo describes a testbed to test various DNS resolvers. The purpose of the testbed is to allow researchers to set up many resolvers and run tests on each. For example, a test might see what the resolver emits when it is priming, or when it is responding to a particular query while using DNSSEC validation.

Root Servers

DNS | Dataset | Tool

Overview page for the DNS root servers. It contains links to general news and all the supporting organizations.

The website features a map with all geographic locations. It contains information about locations, IPv4/IPv6 reachability and IP addresses.

Each root server has its own subdomain in the form of It contains access to historical performance data like:

  • Size and time of zone updates
  • RCODE volume
  • query and response sizes for UDP and TCP
  • traffic volume (packets per time)
  • Unique sources

SIDN Labs DNS Workbench


The DNS workbench is a testbed which allows experimentation how different authoritative DNS servers answer to queries.

It covers five open-source authoritative servers, namely Bind9, Knot, NSD4, PowerDNS, and Yadifa. The workbench contains zones to test the support for many different resource record (RR) types, DNSSEC validation and how invalid zones are managed, delegations, zone transfers, and potentially more.

Find the project on GitHub.

Shadowserver Dashboard

DNS | Dataset | Malware | Network

The Shadowserver Scanning projects performs regular Internet wide scans for many protocols. The dashboard shows the gathered data about botnet sinkholes, Internet scans, honeypots, DDoS, and IoT data. This includes information about the size of botnets, the number of IP addresses with open ports like MySQL, the botnets as seen by honeypots, or the used protocols for DDoS attacks.

The blog post provides an introduction to the new dashboard.

Shadowserver Scanning Project

DNS | Dataset | Malware | Network

The Shadowserver Scanning projects performs regular Internet wide scans for many protocols. They scan for four main types of protocols:

  1. Amplification protocols, e.g., DNS or NTP
  2. Botnet protocols, e.g., Gameover Zeus or Sality
  3. Protocols that should not be exposed, e.g., Elasticsearch, LDAP, or RDP
  4. Vulnerable Protocols, e.g., SSLv3

The website is a great resource to get general statistics about the protocols, like the number of hosts speaking the protocol, their geographic distribution, associated ASNs, and the historic information.

Subdomain Enumeration by Bastian Kanbach

DNS | DNSSEC | Tutorial

The blog post about Subdomain Enumeration in the APNIC blog provides a great overview of the techniques, defenses, and tools for it. Subdomain enumeration is the act of learning available subdomains in a zone using DNSSEC. This is with NSEC records and somewhat harder with NSEC3, due to hashing of names. The blog goes explains how online signing can combat subdomain enumeration, using the white lies or the black lies strategies. Lastly, it links to tools for performing these attacks.

Wildcard DNS for IP Addresses

DNS | IP | Network | Tool

These services allow you to create a domain name for any IP address. The IP address is encoded into the domain name. An overview of different services can be found here.

Online Services

  • provides IPv4 only

    • Supports both . and - separators.
    • resolves to
    • resolves to
    • resolves to
    • resolves to
  • provides IPv4 and IPv6

    • Supports both . and - separators.
    • Provides the ability to use the service with your own branding.
    • resolves to
    • resolves to
    • resolves to
    • – resolves to ::1
    • resolves to 2a01:4f8:c17:b8f::2
  • provides IPv4 and IPv6

    • Supports both . and - separators.
    • resolves to
    • resolves to
    • resolves to
    • resolves to 2a01:4f8:c17:b8f::2

Self-hosted Options

  • hipio is a Haskell service for IPv4.

ZMap Project

DNS | IP | Network | Tool

Different utilities for network scanning. Most importantly, the zmap component, which is a packet scanner for different protocols. It also contains other tools like ways to iterate over the IPv4 address space and denylist/allowlist management.

DNS | IP | Network | Tool

dnskv: DNS-based Key-Value Storage

DNS | Tool

This is a custom DNS server which allows setting and retrieving text-based data. New values can be written as subdomains and retrieved via a normal TXT lookup.

  • To set a key: dig txt +short
  • To get a key: dig txt +short

The service provides many extra options like setting an expiry time or the TTL. DNS-based Key-Value Store

DNS | Tool

This is a custom DNS server which allows setting and retrieving text-based data. New values can be written as subdomains and retrieved via a normal TXT lookup.

  • To set a key: dig txt +short
  • To get a key: dig txt +short
  • To delete a key: dig txt +short

mess with dns

DNS | Tool

"mess with dns" is a tool which allows you to experiment with DNS. The website allows creation of resource records of many types. They are all within a custom 3rd level domain. The website also shows the DNS requests the authoritative DNS server received.