- From: Shel Kaphan <sjk@amazon.com>
- Date: Thu, 6 Jun 1996 09:03:04 -0700 (PDT)
- To: Koen Holtman <koen@win.tue.nl>
- Cc: Shel Kaphan <sjk@amazon.com>, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
Koen Holtman writes: > Shel Kaphan: > > > >In addition to knowing if there is a server somewhere in the chain that > >supports byte ranges, it would be useful to be able to tell what the > >minimum HTTP version is in a chain of servers. > > The Via header allows, among other things, the detection of the > presence of 1.0 servers in the chain. > > >--Shel > > Koen. > It would, if it were there in earlier versions of the protocol. In 1.0 all you get is mashed User-Agent headers and the occasional Forwarded header, if you're lucky. It would be far more reliable to make it mandatory for 1.1 servers to "report on their neighbors". Here's a User-Agent header from today's logs: Mozilla/2.02 (Win16; I) via proxy gateway CERN-HTTPD/3.0 libwww/2.17 Modified via PRD proxy gateway via Harvest Cache version 1.4pl2 via Harvest Cache version 1.4pl3 I guess you can "back out" the information by looking for "via" or "forwarded" in the user-agent string, or looking for a "Forwarded" header, and if either is present assume there's a 1.0 or earlier proxy in the chain. That's fairly ugly and probably not very reliable though. --Shel
Received on Thursday, 6 June 1996 09:07:31 UTC