DNS always updating

[Kevin Darcy]

G Berg wrote:

>Hi there!
>
>Jim Reid wrote:
>  
>
>>    >> If I do not run my script and just reload the nameserver
>>    >> without having made any changed to the zonefiles, he just
>>    >> starts and then does nothing.
>>
>>    >> So my question is: How does bind determine whether changes have
>>    >> taken place to that he needs to send notifies and reload all
>>    >> the files? 
>>
>>The name server remembers the time when it last loaded a zone file.
>>On a reload, it compares that against the time that the filesystem
>>says the zone file was last changed. If the zone file is newer than
>>the timestamp when the server last loaded the zone, the zone gets
>>loaded again. So your script should be fixed so that it doesn't
>>generate new copies of zone files that haven't changed. You should
>>also consider generating the files in some other part of the
>>filesystem and then having the new or changed ones copied to the place
>>where the name server loads them. ie Don't generate the files directly
>>into the name server's working directory.
>>
>>    
>>
>
>Thanks for your help.
>
>That was my thought as well and I changed my script so that only those 
>zonefiles are created newly, which have to be modified. But this does 
>not help.
>
Perhaps the problem is that you're doing a full reload. You can use 
"ndc" to do zone-specific reloads for only the zones that have changed, 
e.g. "ndc reload example.com".

>I guess the problem is, that my named.conf is rewritten every time. May 
>this be true? I need to rewrite it since there may be zones added or 
>deleted.
>
That too can be handled via "ndc": do an "ndc reconfig" after changing 
named.conf if you want the running named process to notice newly created 
or deleted zones. Do this before any reloads.

- Kevin