Odd www log entries: Accelerated browsing the culprit?

[Ben Scott]

On Nov 11, 2007 9:52 AM,  <VirginSnow at vfemail.net> wrote:
> How can the browser possibly know what to download for a page if
> it hasn't even seen the page yet?

  One other explanation could be that the HTML page is cached on the
client, but the prerequisite resources (images, CSS, etc.) are not
cached or have expired.  Is the HTML being served with different cache
control/expiry headers?

> Could I be seeing some sort of web acceleration technology?

  Seems possible, even likely.  Those things have a reputation for
being bad implementations of a bad idea.

  Are you only getting these from a handful of client IP addresses?
That would indicate it's a handful of users running such accelerators.

  Does the "User Agent" HTTP header provide any clues?

> Some (but not all) of the requesting IP addresses reverse-resolve to
> what look like end-user addresses (xyz-123-45-67-89.pool.someisp.con)
> but some of them return NXDOMAIN.

  NXDOMAIN also often equates to an "end-user address".

  (Aside: Gee, suddenly, network discrimination isn't so cut-and-dry, eh?)

-- Ben