Adrián Bíro

DNS stuff

dig

dig -r ptr 185.199.110.153.in-addr.arpa

Reverse DNS lookups

dig -x 185.199.110.153
nslookup 185.199.110.153

Specify DNS server

dig adrianbiro.github.io +noall +stat
dig @1.1.1.1 adrianbiro.github.io +noall +stat

DNS Resource Records

DNS Records Cloudflare

A Record: Links the domain to an IPv4.
MX Record: Mail exchange records direct emails sent to domains to the correct mail server.
NS Record: Name server records to a set of DNS servers.
TXT Record: Text records store.
SOA Record: Start of authority records like, primary name server, the responsible party, a timestamp for changes, the frequency of zone refreshes, and a series of time limits for retries and abandons.
TTL: Time to live in cache each for DNS query.
ANY: Return every type of DNS record it can find.

dig + spf

Sender Policy Framework (SPF) definition via a DNS TXT

$ dig github.com TTL
$ dig github.com TXT
$ dig +noall +answer aws.amazon.com CNAME
aws.amazon.com.         15      IN      CNAME   tp.8e49140c2-frontier.amazon.com.

On windows or use dog

Resolve-DnsName -Name google.com -Type a

Access DNS zone data for the different top-level domains

IANA domains root files

dig +noall +answer +noidnout +onesoa @f.root-servers.net . AXFR
dig +short ns edu.
dig +noall +answer +noidnout +onesoa @$(dig +short ns arpa. | head -1) arpa AXFR

nslookup -query=a google.com
dig a +noall +answer google.com
host -t a google.com

Get subdomains

On Wolframalpha > Web statistics for all of <domain> > Subdomains

URL

URLs: It’s complicated…

Links

Get random domain from tranco list cut -f, -d2 tranco.csv | shuf | head -n1

IP Geo Location

IP2location

BIND 9.x Security Technical Implementation Guide for DoD

BIND DNS Stig recomendations

DNS tools by ISC

ASN Lookup asn arin

Free & Public DNS Servers

Provider	Primary DNS	Secondary DNS
https://developers.google.com/speed/public-dns/	8.8.8.8	8.8.4.4
https://controld.com/free-dns/	76.76.2.0	76.76.10.0
https://www.quad9.net/	9.9.9.9	149.112.112.112
https://www.opendns.com/	208.67.222.222	208.67.220.220
https://1.1.1.1/dns/	1.1.1.1	1.0.0.1
https://cleanbrowsing.org/filters/	185.228.168.9	185.228.169.9
https://alternate-dns.com/	76.76.19.19	76.223.122.150
https://adguard-dns.io/en/public-dns.html	94.140.14.14	94.140.15.15

Flush DNS

PS C:> Get-DnsClientCache
PS C:> Clear-DnsServerCache
PS C:> dnscmd /clearcache
PS C:> Clear-DnsClientCache
PS C:> ipconfig /flushdns
PS C:> ipconfig /displaydns

systemctl is-active systemd-resolved
resolvectl statistics
sudo journalctl -u systemd-resolved
resolvectl flush-caches 
sudo killall -USR1 systemd-resolved

sudo killall -HUP dnsmasq

In Google Chrome chrome://net-internals/#dns in Mozilla Firefox about:networking#dns

PGP and DNS

The complete guide to publishing PGP keys in DNS

Misc

Show my IP dig +short myip.opendns.com @resolver1.opendns.com