dns

If you need to find out all the sub-domains of a given domain name, you can try AXFR request.

This hint works only if the NS that you are querying is configured to allow AXFR requests.

Not all name servers allow AXFR protocol queries. Most of them return “Transfer failed”.

The first thing that you have to do, is to find out the AUTHORITY NAME SERVER(s) for the required DOMAIN NAME e.g zonetransfer.me:

$ dig zonetransfer.me

Look under the AUTHORITY SECTION:

;; AUTHORITY SECTION:
zonetransfer.me.	7122	IN	NS	ns16.zoneedit.com.
zonetransfer.me.	7122	IN	NS	ns12.zoneedit.com.

In this case zonetransfer.me has 2 name servers: ns12.zoneedit.com and ns16.zoneedit.com.

Now you can query one of these servers for the sub-domains of zonetransfer.me:

$ dig @ns12.zoneedit.com zonetransfer.me AXFR

Here is the result:

; <<>> DiG 9.9.2-P1 <<>> @ns12.zoneedit.com zonetransfer.me AXFR
; (1 server found)
;; global options: +cmd
***
zonetransfer.me.	7200	IN	NS	ns16.zoneedit.com.
zonetransfer.me.	7200	IN	NS	ns12.zoneedit.com.
zonetransfer.me.	7200	IN	A	217.147.180.162
zonetransfer.me.	7200	IN	MX	0 ASPMX.L.GOOGLE.COM.
***

There are several reasons why you may want to use alternative DNS servers:

• Speed up your web browsing;
• Improving your security;
• Backup solution when your ISP servers are down.

Here is a list of Free public DNS servers.

Google Public DNS

Google Public DNS – Free DNS server list.

# For IPv4:
nameserver 8.8.8.8
nameserver 8.8.4.4
# For IPv6:
nameserver 2001:4860:4860::8888
nameserver 2001:4860:4860::8844

OpenDNS

OpenDNS – Free Public DNS IP address.

nameserver 208.67.220.220
nameserver 208.67.222.222

Norton ConnectSafe

Norton ConnectSafe – Free DNS server list.

nameserver 198.153.192.1
nameserver 198.153.194.1
# A - Security (malware, phishing sites and scam sites):
nameserver 198.153.192.40
nameserver 198.153.194.40
# B - Security + Pornography:
nameserver 198.153.192.50
nameserver 198.153.194.50
# C - Security + Pornography + Non-Family Friendly:
nameserver 198.153.192.60
nameserver 198.153.194.60

Comodo Secure DNS

Comodo Secure DNS – Free Public DNS IP address.

nameserver 8.26.56.26
nameserver 8.20.247.20

DNS Advantage

DNS Advantage – Free Public DNS IP address.

nameserver 156.154.70.1
nameserver 156.154.71.1

ScrubIT

ScrubIT – Free Public DNS IP address.

nameserver 67.138.54.100
nameserver 207.225.209.66

Level 3 Communications

Verizon (Level 3 Communications) – Free Public DNS IP address.

nameserver 4.2.2.1
nameserver 4.2.2.2
nameserver 4.2.2.3
nameserver 4.2.2.4
nameserver 4.2.2.5
nameserver 4.2.2.6