Negative caching config

[Kevin Darcy]

Correct. And generally speaking you wouldn't want to. Keeping a record 
in cache beyond its expiration time is like eating food or taking 
medicine that is beyond its expiration date: you might survive, but why 
take unnecessary chances? :-)

- Kevin

Michele Chubirka wrote:

>Okay, but I can't *increase* someone else's TTL with these settings, can I?
>If my max-cache-ttl is set to 2 hours and a record from an outside
>server/zone has a TTL of 1 hour, then it will live for 1 hour, right? And
>the same for max-ncache-ttl?
>
>-----Original Message-----
>From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org] On Behalf
>Of Kevin Darcy
>Sent: Thursday, March 04, 2004 6:30 PM
>To: comp-protocols-dns-bind at isc.org
>Subject: Re: Negative caching config
>
>
>No, max-ncache-ttl only limits the negative caching of answers you get 
>*from* other nameservers/resolvers. What you set in your zone files are 
>the negative-caching values you give *to* other nameservers/resolvers. 
>They have no effect on each other.
>
>                                                                         
>                                                                  - Kevin
>
>Michele Chubirka wrote:
>
>  
>
>>By setting the negative TTL in named.conf, doesn't that override any
>>settings in the individual zone files?
>>
>>----- Original Message -----
>>From: "J Marquez" <sunsol19712003 at yahoo.es>
>>To: "Barry Margolin" <barmar at alum.mit.edu>;
>><comp-protocols-dns-bind at isc.org>
>>Sent: Thursday, March 04, 2004 3:36 AM
>>Subject: Re: Negative caching config
>>
>>
>> 
>>
>>    
>>
>>>Thank you very much Barry.
>>>
>>>Best regards!
>>>Barry Margolin <barmar at alum.mit.edu> wrote:
>>>In article ,
>>>J Marquez wrote:
>>>
>>>   
>>>
>>>      
>>>
>>>>We are pretty new by configuring DNS. We would like to activate
>>>>     
>>>>
>>>>        
>>>>
>>"negative
>> 
>>
>>    
>>
>>>>cache" in our Cache DNS's. We have searched the archives to look for a
>>>>specific procedure, but haven't found anyone (sorry, if this question is
>>>>     
>>>>
>>>>        
>>>>
>>>All BIND 8 or 9 releases from the last 5 years implement negative
>>>caching by default; you don't have to do anything to enable it.
>>>
>>>   
>>>
>>>      
>>>
>>>>alredy solved in one of them). We think we have to add
>>>>"max-ncache-ttl
>>>>in named.conf but not sure if its necessary additional steps or it does
>>>>matter the position of this line inside named.conf
>>>>     
>>>>
>>>>        
>>>>
>>>"max-ncache-ttl" just allows you to set a cap on the negative cache
>>>time. It's not normally needed.
>>>
>>>   
>>>
>>>      
>>>
>>>>Also for a cache DNS, what would be the ideal TTL for Negative Cache?
>>>>     
>>>>
>>>>        
>>>>
>>>That's not controlled on the caching DNS, it's set in the SOA records of
>>>the domains.
>>>   
>>>
>>>      
>>>
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