[14528] in North American Network Operators' Group

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Re: Web caching liability

daemon@ATHENA.MIT.EDU (Dan Mosedale)
Tue Jan 6 12:09:13 1998

To: nanog@merit.edu
From: Dan Mosedale <dmose@netscape.com>
Date: Mon, 05 Jan 1998 16:56:34 -0800

Dean Gaudet wrote:

> The DNS thing isn't something that only AOL is innocent of.  Netscape
> navigator up through the 3.x versions (I haven't tested the 4.x versions,
> they may have fixed it) caches DNS responses for the lifetime of the
> browser.  Given that some folks on stable unix machines are able to keep
> their browser open for months this sucks.

In current versions of Netscape, IP addresses are cached for fifteen minutes.  To
tweak this, add or change the following line in your prefs.js file

user_pref("network.dnsCacheExpiration", 900) // The integer is the timeout in
seconds

> One might argue it has something to do with the lack of timeout information in
> the
> gethostbyname(3) API.

This is, in fact, why it was implemented that way -- gethostbyname is available on
pretty much every platform.  I've pointed the folks responsible for this code to
res_query() related documentation and code, so this may make it into a future
version.

Dan




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