In a previous post, I discussed DNS and what it does. It was a brief overview of the DNS concept and how an improperly configured DNS entry or a malfunctioning DNS server can affect us. Now that we have some background, did you know that you could find the master DNS server or servers for any domain? That is, you can find the one or two DNS database servers out on the Internet that tells all of the other DNS servers what the IP address for the domain is?
Okay, maybe you are confused, if so please see my earlier post for more background, but I will try to break it down a bit. We know that DNS gives us an IP address for a domain name. Example: www.google.com is at IP address 220.127.116.11. We also know that our computers look to a DNS database server to get that info. And our ISPs are telling our computers what DNS database servers to use for IP address lookups. Okay, now that we have done some review, we can look at how to find the DNS server for any domain.
There are two ways we can do this, via a web page, or using our own computers network utilities. Lets start with the web page first. Open your web browser and head to www.dnswatch.info.
Enter a domain name in the Hostname or IP box. Set the type to NS (for Names Server) and click resolve.
Check the table in the center of the page.
Here is the information about which DNS servers are updating the rest of the world with the IP addresses for uxking.com. Uxking.com has 3 DNS servers (most domains have at least two for redundancy). The info in the table is pretty self explanatory, except for the TTL. The domain we looked up, the type of DNS record (which is Name Server), the number of seconds the record should be cached on other DNS servers (TTL), and the hostnames of the DNS servers (Answer).
Lets use the other tool I mentioned earlier to do the same thing.
Open a Terminal Window (MAC or LINUX) or Command Window (PC). The tool works the same on either of these platforms, but I’m using a MAC right now, so I’ll show you what the output looks like on a MAC.
Open your terminal window and type nslookup.
> set type=ns
www.uxking.com canonical name = uxking.com.
uxking.com nameserver = ns1.lnhi.net.
uxking.com nameserver = ns2.lnhi.net.
Authorative answers can be found from:
You should get a “>” prompt to indicate that you are now entering commands for nslookup. As you can see from above, I set the type of record I am seeking to be NS (name server) bye typing set type=ns. Next I simply typed the domain I was interested in, www.uxking.com. The output is similar to what you will find from the browser based tool, minus the TTL info. You can clearly see the nameservers listed for www.uxking.com.
You can continue to type any domain into either of the tools to find their nameservers. Try your own domain, or google.com, yahoo.com. Some domains have quite a few nameservers.
Go ahead and experiment with the nslookup tool. Try setting the type to ALL (set type=all) and see what other info you get. Also, try removing the www from the domain too.