Hi all, I'm struggling with the configuration of a PHP based content management system served from Apache behind a squid 2.6 reverse proxy. Specifically, it's serving out stale content, ie. responses that are past their "Expires" time. I've added "must-revalidate" to the "Cache-Control" header but squid is still caching the (old) response. I thought it would re-cache the URL after the "Expires" time. Is that not the case? Also note, the application is configured to send a "304 Not Modified" Status-Code where appropriate. This request was made at Mon, 20 Sep 2010 05:05:45 GMT but is still being severed by squid hours after becoming "stale". HTTP/1.0 200 OK Date Sun, 19 Sep 2010 03:42:44 GMT Server Apache/2.2.3 (Red Hat) X-Powered-By PHP/5.1.6 Expires Sun, 19 Sep 2010 12:34:05 GMT Cache-Control max-age=43200, public, must-revalidate Pragma cache Last-Modified Fri, 17 Sep 2010 06:50:06 GMT Vary Accept-Encoding,User-Agent,X-SSL Content-Encoding gzip Content-Length 5009 Content-Type text/html; charset=utf-8 Age 1 X-Cache HIT from webcms-prod02.mysite.com X-Cache-Lookup HIT from webcms-prod02.mysite.com:3128 Via 1.0 webcms-prod02.mysite.com:3128 (squid/2.6.STABLE21) Connection keep-alive -- Regards, Sean. This e-mail is confidential. If you are not the intended recipient you must not disclose or use the information contained within. If you have received it in error please return it to the sender via reply e-mail and delete any record of it from your system. The information contained within is not the opinion of Edith Cowan University in general and the University accepts no liability for the accuracy of the information provided. CRICOS IPC 00279B