Can I manually update local DNS cache?

[Alex Shi]

I have a DNS running on RH 7.1 home server. I am just
wondering how this DNS regularly update it's local cache
and how can I force it to update right away?

Alex

[Mark Damrose]

"Alex Shi" <chp...@stonix.com> wrote in message
news:abjjak$dfj9$1...@isrv4.isc.org...

>
> I have a DNS running on RH 7.1 home server. I am just
> wondering how this DNS regularly update it's local cache
> and how can I force it to update right away?

When you start your DNS server it only knows about the dns domains you are
serving and the root zones. When a client requests a record, your server
goes to the root servers and follows the chain down to the server that has
the info. Your server caches all those answers for as long as the other
administrators have allowed it. If the client asks for the same record it
is returned out of cache. If the client asks for another record served by
any of the DNS servers it has already contacted - your server contacts that
one directly without going all the way back to the root.

You can not manually insert anything into your cache. The only way to force
your server to update before old data has expired is to completely clear the
cache. You can do that by restarting the server or rndc flush with bind 9

>
> Alex
>

[those who know me have no need of my name]

<abjjak$dfj9$1...@isrv4.isc.org> divulged:

>I have a DNS running on RH 7.1 home server. I am just
>wondering how this DNS regularly update it's local cache

automatically, according to the data it receives.

>how can I force it to update right away?

rndc flush

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