caching of "server fail" BIND9

[Matus UHLAR - fantomas]

Hello,

please configure your mailer to wrap lines below 80 characters per line.
72 to 75 is usually OK.

Thank you.

On 24.08.10 09:49, Len Conrad wrote:
> We just had a problem where a BIND9 running on our postfix MX
> 451-rejected-as-unknown-domain all msgs from @sender.domain for 9 days.
> 
> "rndc flush" allowed the domain to be resolved immediately and its
> messages accepted.
> 
> When the BIND reports "server fail", rather than a negative answer with
> neg-TTL, how long is SRV FAIL cached in BIND9?  RFC2308 says "no longer
> than 5 minutes".

this applies for "server failure" and "dead/unreachable" responses, not for
responses as "name error" or "no data". 

> We do not know whether unknown domain's NS was really SRV FAIL for 9 days.

each zone defined the negative TTL, stored in SOA "minimum" field (which has
now only this usage therefore it should be renamed).

check the SOA of "sender.domain" to see how big the TTL is.

-- 
Matus UHLAR - fantomas, uhlar at fantomas.sk ; http://www.fantomas.sk/
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