[clue-tech] BIND

[Nate Duehr]

Mike Staver wrote:
> I found a fix - a very nice config option for BIND.  Simply add this:
> 
> also-notify {
>    10.0.0.12;
>    10.0.0.17;  };
> 
> It can be placed in the general options in named.conf, or per zone file. 
>  I need my DNS changes to be consistent across the board - if I modify a 
> zone, I want all authoritative servers to show the correct record as 
> soon as possible.  By default, BIND appears to send out notifies to the 
> NS records in a zone file. By using also-notify, you can tell the local 
> IPs of these servers which are on the same subnet as the master.
> 
> William wrote:
>> My slave DNS providers are on other networks and I don't worry at all 
>> about pushing changes to them in real time.  As I learned it, TTL and 
>> expiry settings are what actually dictate when slaves update against 
>> the master.  When that update period lapses, the slaves query the 
>> master.  If, and only if, the serial number differs, a zone transfer 
>> takes place.  Otherwise, the slaves maintain their local cache by 
>> updating only the expiry period, conserving bandwidth and processing 
>> cycles.  My logs seem to indicate this behavior.  I'll see no zone 
>> transfers for a while, until I make a zone update.  That night 
>> (several hours later), a zone transfer occurs.  My recommendation:  
>> don't worry about it; this is normal.

Yes, I was going to mention this - you should always try to do NOTIFY's 
to your slaves so there's never a "split-brain" with different serial 
numbers and different entries.

Nate