Hi. I have a couple of DNS questions.

First, I bought a domain name (lets say www.buckrogers01.com for now). I want to run the DNS servers for this domain at home, but when I try to enter the primary DNS server's address (my IP). I get an error (on the website, but I think it's a general problem) saying that I have to enter a hostname. That's fine, I thought, except that the whole idea of a DNS server is to translate hostnames to IPs. So how does this work, if I enter a hostname then that must also be translated using another DNS server, and if that is specified by a hostname then this would go on forever.

I also noticed that for the DNS zone file for phase8.net, the primary and secondary dns servers are ns0 and ns1.phase8.net. But how are those hostnames resolved, as the zone record FOR phase8.net contains the hostnames for DNS servers (which resolve the hostnames). I thought that the DNS servers which would resolve the domain name (any domain) would be entered into the information stored with the domain on a root DNS server, but how can a host be resolved when the name server's (that are meant to resolve hostnames for the domain) use a domain they are meant to be resolving for.

Sorry for the complexity, I'll try and post a diagram later.

Thanks in advance, Buck

You would normally specify an IP address as your DNS servers due to the very recursion problem you've identified. If the config on a host requires you to enter a name then it must expect to resolve that name from somewhere. The most obvious place is the /etc/hosts file which is a static list of name to IP mappings. I would define ns1.blablah.com as the dns server in the app then put

ns1.blahblah.com 1.2.3.4

in the hosts file.

wow, someone actually understood me. So are you saying that I should request my domain controller (www.simply.com) to update my domain info with actual IP's (as their website based nameserver changing only accepts hostnames)

Not quite. /etc/hosts is a file that sits on your PC. When you tell your PC that to resolve names it needs to go to ns1.simply.com, your PC needs to resolve that name first to be able to resolve anything else and now your stuck in your logical loop.

However the other place to resolve names is in your PCs local /etc/hosts file. You yourself can put entries in that file for name resolution. As you are using DNS the only thing you need to resolve locally is ns1.simply.com. After that all other name resolution will be done via ns1.

As I said, most apps allow you to put in IP's, but if one insists on a name for the nameserver then you will have to resolve the name servers name locally before you can send name reolution requests to it.

Think of directory enquiries as an example. You don't know someones phone number, so you need to ring directory enquiries to find it. Unfortunately you don't know the number for directory enquiries either. Luckily you made a note of it on your notice board, so you resolve the name "directory enquiries" to 192, then by calling 192 you can now resolve "charlie farnsbarnes" to 011612287646, or indeed any other name to a number. Its that first link in the chain you need to establish or the rest won't work.


I think that /etc/hosts is checked before DNS is used so in effect you can speed up access to a site by placing an entry in your hosts file, you just lose the dynamic element. i.e. if www.simply.com is actually 4 servers then DNS would respond to requests in a round robin fashion as a primitive load balancer, or if the server IP changed you would need to manually change the entry. So like in any engineering there are pro's and cons to everything.

I understand how all the hosts file and DNS works, but on the web management system on simply's site, when I try and change the nameservers for my domain to another dns server, I cannot enter an IP, only a hostname. So how can I transfer the nameservers for my domain to my own server (which has a static IP).

Also, in domai records at InterNIC (for example) does a normal domain record hold IP addresses for nameservers or hostnames.

I don't understand how the domain info (whois info) can hold nameservers which have a domainname, (for example ns0.phase8.net). Surly this would cause a loop in name resolution.

This is how I understand name resolution works:

COMPUTER contacts DNS server (specified either when a DHCP lease was obtained, or manually entered) --

DNS server contacts ROOT servers (which have a known IP), to find the DNS servers responsible for the requested domain, the domain and the DNS server info is stored on the root computer of the TLD --

DNS server contacts DNS server responsible for the domain, as looked up in the root servers), to find out IP of requested hostname (e.g. www).

DNS server returns IP --

Computer contacts the IP.

Now the DNS servers that are returned by the ROOT server should be IP addresses, (I think), so how come hostnames can be returned. (as the whole process would start again)

Please correct me if I'm wrong...


What I am trying to set up is a home web server (which is also running a DNS server), where I have total control over the DNS info IE I'm editing the zone file). However I cannot transfer nameserver control from simply's servers to my own. I have a staic IP. Do you know how I could accomplish this without using a 3rd party service (IE www.no-ip.com).

Thanks for all the hope so far

When it ask for a hostname enter a hostname (lets say ns1.buckrogers01.com) . Anything you want to see as your master dns. After clicking next/save it will ask for an ip
Enter your static ip & wait to refersh the zone

It it doesnt ask for an ip (to match ns1.buckrogers01.com) means that all of us would need an DNS server outside our namezone to host our name zone
I hope i helped

thanks, there system doesn't ask for an ip, so i'm stuck with them

I'm not sure its that simple. At present the zone info resides on simply's DNS server. To host the zone info yourself this info would need to be removed from simplys DNS server and put on yours. Simply's DNS server would then need to be told that your server is authoritative for this zone. This normally involves reconfiguring the ISP's DNS servers and I hardly think they are going to let you do that yourself. Are you sure the thing your trying to configure means what you think it does? Prehaps you need to talk to them directly to clear this up as we are just guessing.

What you need to do is ask simply DNS if they support Glue records. Glue records are the standard for alleaviating this recursion problem you are talking about.

but how do I get the domain info (hosted on one of the TLDs) for my domain to contain my DNS server, as I cannot specify a hostname, because the computer the DNS will be running on is the one the domain was bought for, and I cannot specify an IP address in the nameserver fields for my domain info

I can't speak for your registrar's web interface, but the ones that I have used to transfer SOA to my name servers involves two steps.

1) Register the name server. This step is needed to populate the appropriate TLD name servers (like a.root-servers.net) with the name/IP of your name server. Look on your registrar's web interface for something like "Manage Registered Name Servers".

2) Once step 1 is completed, then you transfer the SOA for your domain using only the name (ns1.example.com for instance) as you have tried to do already.

That is what a glue record is for. All a glue record is is an A record that is held in the parent domain. e.g. the .com root servers will actually have an A record for your domain describing ns.yourdomain.com. This will allow name resolution of the nameservers within your domain without actually going to your nameservers for resolution.

If your provider supports glue records they will immediatly see that the hostname you are providing for your name servers are within the domain and will ask for and IP. To date the only registrar that i've dealt with that supports glue records is register.com.