Re: positive and negative dns values

On Wed, 29 Mar 2000, Mark Bizzell wrote:

> Hi,
>
> Our squid configuration is having problems access a site which uses dynamic
> ip addresses for their servers ( redundancy) . The DNS ttl the site uses is
> 0 which means that all queries are forced back to their authorative DNS
> server.
>
> THE FAQ refers to how to get true DNS TTL into Squid's ip cache but I don't
> really want to implement this fix unless it's really necessary.
>
> Could someone please explain in a bit more detail how squid uses the
> positive and negative dns ttl values.
>
> If a server is successfully running and connecting to a host on a
> particular IP address (eg 1.1.1.1) and the address changes to 1.1.1.2 does
> the negative_dns_ttl tag force the cache to reexamine the IP address after
> it's cache expiry or does the IP address remain in Squid's ip cache until
> the positive_dns_ttl expires ?

In your example, its the positive_dns_ttl. For a successful lookup,
the answer is used for 'positive_dns_ttl' seconds without making
another lookup.

Duane W.
Received on Thu Mar 30 2000 - 10:47:49 MST