Disable systemd-resolved on Ubuntu/Deb/CentOS

systemd-resolved provide DNS resolver facility in newer version of Linux servers running systemd. I prefer manually editing /etc/resolv.conf and add resolvers. If you are running your own DNS server, then you need to disable systemd-resolved as it listen on port 53, with out disabling the service, you can’t start your DNS server. To disable systemd-resolved, […]

Read More…

Requesting a zone trasnfer with dig

To request a zone transfer using dig, use


See dig […]

Read More…

Wildcard DNS zone in bind

Wildcard DNS zone will act as authoritative DNS for any domain name. This is useful when you have a service like domain name parking service, where customers will change name servers of their domain name to your private label name servers. You need all thse domains get resolved to a specific IP address with out […]

Read More…

Install Unbound DNS caching server

Unbound is an Open source DNS caching and recursive resolver. You can find more about unbound at https://nlnetlabs.nl/projects/unbound/about/ To install unbound on Ubuntu/Debian, run

To start unbound

Set unbound to start on boot

To configure your server to use local name servers provided by unbound, edit file


See dns […]

Read More…

Free DNS Hosting

Free DNS Hosting https://www.cloudflare.com https://desec.io – Open Source. Source code https://yandex.com/support/domain/domain/dns.html https://www.cloudns.net/ https://dns.he.net/ https://www.duckdns.org/ https://www.dynu.com/ https://www.luadns.com https://ns1.com – Developer plan with 1 domain is free Paid DNS Hosting Google Cloud DNS – $0.2 per domain. Traffic will be charged at $0.40 per million queries per month. Free Dynamic DNS https://www.duckdns.org/ […]

Read More…

Delegate a sub domain to DNS server

To point a domain to another server, you can create an A record, point to the server. If your provider only provide name servers and no fixed IP, you can create NS record for your sub domain like

Here is how i added NS record in Amazon Route 53 […]

Read More…


dig is a command line tool like nslookup used to check dns Find Reverse-DNS/PTR using dig, nslookup, host Requesting a zone trasnfer with dig Here is the basic usage

dig have multiple sections, ANSWER SECTION is what you need to look for. After answer section, it shows some info about DNS server used to […]

Read More…

DNS Resolver

CloudFlare announced privacy-first consumer DNS service. IP of CloudFlare public DNS servers are

So far i was using Google Public DNS servers as my resolver.

Quad9 Quad9 is from IMB and Global Cyber Allience. https://www.quad9.net

Other public DNS server is OpenDNS

All these DNS servers have good connectivity in india. I […]

Read More…