Domain Name System – Propagation April 11, 2012
Domain Name System

If you ever update Domain Name System (DNS) records on a DNS server you may use the following method to verify that the updated record(s) are propagating to all internet DNS servers. The server in this example is utilizing Linux CentOS-5.5 64bit.

The command you may use is the following “nslookup” and the manual reveals the following information concerning the syntax of this command.

NAME
nslookup – query Internet name servers interactively

SYNOPSIS
nslookup [-option] [name | -] [server]

For instance, if I wanted to verify the A record for the domain google.com on separate DNS servers then I would use the following command.

# nslookup google.com 8.8.8.8
Server: 8.8.8.8
Address: 8.8.8.8#53

Non-authoritative answer:
Name: google.com
Address: 74.125.115.104
Name: google.com
Address: 74.125.115.105
Name: google.com
Address: 74.125.115.147
Name: google.com
Address: 74.125.115.99
Name: google.com
Address: 74.125.115.103
Name: google.com
Address: 74.125.115.106

# nslookup google.com 128.107.241.185
Server: 128.107.241.185
Address: 128.107.241.185#53

Non-authoritative answer:
Name: google.com
Address: 209.85.229.147
Name: google.com
Address: 209.85.229.99
Name: google.com
Address: 209.85.229.104

# nslookup google.com 151.197.0.38
Server: 151.197.0.38
Address: 151.197.0.38#53

Non-authoritative answer:
Name: google.com
Address: 74.125.91.104
Name: google.com
Address: 74.125.91.103
Name: google.com
Address: 74.125.91.106
Name: google.com
Address: 74.125.91.105
Name: google.com
Address: 74.125.91.147
Name: google.com
Address: 74.125.91.99

The examples above query the Google, Cisco and Verizon DNS servers. During a search on the internet, I found the following list of public DNS servers that you may use.

Google
======
8.8.8.8
8.8.4.4

Level 3 Communications (Broomfield, CO, US)
=============================
4.2.2.1
4.2.2.2
4.2.2.3
4.2.2.4
4.2.2.5
4.2.2.6

Verizon (Reston, VA, US)
================
151.197.0.38
151.197.0.39
151.202.0.84
151.202.0.85
151.202.0.85
151.203.0.84
151.203.0.85
199.45.32.37
199.45.32.38
199.45.32.40
199.45.32.43

Cisco (San Jose, CA, US)
================
64.102.255.44
128.107.241.185