plz help me configure root server

[Maaz]

Dear Gurus
This is not a requirement but simply I m just learning.

I want to configure the Root Dns server in my lab environment for testing. I have done the following
in /etc/named.conf

zone "." IN {
type master;
file "root.file";
};

cd /var/named/chroot/var/named
vi root.file(i have attached the "root.file")

Plz help me creating proper config of Root server

Regards
Maaz

[Alexander Chuzhoy]

you didn't specify what exactly you'd like to learn, but nevertheless I'm gonna try:


com. IN NS ns1.com-server.net.

this line means that to resolve hosts from com. domain we'll have to contact ns1.com-server.net server first.

On ns1.com-server.net (11.0.0.1)create a zone "com" and propogate it with hosts/domain in similar way.
host1.com. IN A x.x.x.x
If you want to ass sub domain, then:
subdomain.com. IN NS somedns.com.
somedns.com. IN A x.x.x.x

Here in case of subdomain you actually put the hostname of DNS server that is responsible for that domain and on next line the IP of that DNS.

If you want to create a local root server to your organization, then simply remove the "." zone.

And by the way if the IP is local to your organization, then 11.0.0.1 is probably not a good choice. I'd go for reserved addresses, but you probably know that already. :)

[Maaz]

Dear Alexander Chuzhoy Thanks for response/help

>you didn't specify what exactly you'd like to learn
I wana learn how to conigure the root dns server.

>If you want to create a local root server to your organization, then simply >remove the "." zone.
did u mean that the server which is the Root dns server in my test lab environment doenst have the "." zone, as i have mentioned in the above(1st) post.. i.e on the Root server I have created a "." zone as
/etc/named.conf
zone "." IN {
type master;
file "root.file";
};
Did u mean I have remove the above code from my root server ? if yes then what zone should I have to create on the root server ?

[Alexander Chuzhoy]

First read a quote:
"Root Server - A root server is installed to be the source for resolving names for an hierarchical namespace. The root is the top of the hierarchy containing all organizational domain zone names. Names that cannot be resolved in the domain zone names are passed to the root DNS server if specified."

If dns clients that are configured against you DNS server can't find authoritative answer on your server, then they go to "." zone (if one exists).
if (for example) you'd look for www.microsoft.com (I hope you wouldn't :) )
then in file that's for "." zone first there's an attempt to locate "com." .If not found - respective message returned to a client. If found entry like:

com. IN NS root-server.net.
root-server.net. IN A 11.0.0.1

Then root-server.net is contacted in attempt to find "com" zone on it.

If such zone is found on it then there's an attempt a line similar to this:
microsoft.com. IN NS somednsservername
somednsservername IN A someIP

Then there's an attempt to go to somednsservername and to fin a file that's for "microsoft.com" and inside this file a line for search would be:
www.microsoft.com. IN A x.x.x.x

if found-this IP (x.x.x.x) would return to a client ,if not -respective message...


Hope it helps.

[Maaz]

thanks for support Alexander Chuzhoy.
i think I havent clear what I wana ask.

Ok, I know the DNS concept. and I just wana know/ask that to configure the root dns.. is my configurations are fine/ok

On the Root dns server I have created a "." zone as
zone "." IN {
type master;
file "root.file";
};
1, on the root dns server does the above mentioned zone is ok, or there is something mising/wrong ?
2, is the root.file(attached) is ok ?

Regards
Maaz

[Alexander Chuzhoy · Accepted solution]

The file's syntax looks OK.

There's a working example of such file though. The file called named.ca and it's probably located here:
/var/named/chroot/var/named/named.ca

Never the less I'm attaching it also-so you might wanna take a look.
P.S.
By the way by default the zone's type is hint
and not master.
If you'd like to know more about it:
http://www.zytrax.com/books/dns/ch7/zone.html