dns question

[Don Russell]

Ed Greshko wrote:
> Don Russell wrote:
>   
>> I added some information to my named configuration so sendmail could
>> resolve the reverse look up of the private LAN addresses.... or at least
>> get an error quickly instead of timing out
>>
>> In order for this to work, I manually changed /etc/resolv.conf ,
>> deleting the exisiting nameserver statements, and adding nameserver
>> 127.0.0.1
>>
>> Works great.... UNTIL the network is restarted and the resolv.conf file
>> is rewritten.... then the nameserver statements are back to the
>> addresses from the ISP obtained via DHCP.
>>
>> So, for an interesting experiment, I reconfigured the dhcp server in my
>> router (cisco) to not pass the ISP DNS addresses to my server, instead
>> use 127.0.0.1
>>
>> Frankly, I wasn't expecting the server to be able to resolve any other
>> addresses.... but it does....
>>
>> Why? Seems silly to be asking why something DOES work.... but I don't
>> understand how it can be resolving names like google.com, ibm.com etc
>> etc, when it was not told which dns servers to use, other than "ask
>> yourself"....
>>
>> What am I missing? ;-)
>>     
>
> In your named.conf do you have something like:
>
> zone "." {
>      type hint;
>      file "named.root";
> };
>
> If so, you have told your DNS server what it needs to do.


Yes, I just looked at that... the file has a different name (named.ca), 
but it seems to describe all the root servers....

I gather that means my FC5 box is now using the root servers directly to 
resolve addresses instead of "lower", possibly caching, servers.

hmmm, that doesn't sound good... :-(  But I'm pretty new to dns details....