RE: [squid-users] Cache-Control problems with Korean sites

I used telnet to connect to the problem web server and sent a minimal HTTP request. The web server returned a page, so I tried again adding a header from the trace one at a time until I did not get a response. I only tried one value of Cache-Control, max-age=0.

I've tried accessing the Korean Government sites from other proxy servers around the world and I get the same behavior. I know the problem isn't with the proxy server's ISP, but rather with the Korean Government sites.

Mike Mitchell

-----Original Message-----
From: Amos Jeffries [mailto:squid3_at_treenet.co.nz]
Sent: Tuesday, July 21, 2009 2:37 AM
To: Mike Mitchell
Cc: squid-users_at_squid-cache.org
Subject: Re: [squid-users] Cache-Control problems with Korean sites

Mike Mitchell wrote:
> We're having problems accessing Korean Government sites like parcel.epost.go.kr and www.g2b.go.kr<http://www.g2b.go.kr> from a squid cache that is physically in Seoul, Korea. I performed network captures and found that if the request included a 'Cache-Control' header the remote server did not send TCP ACK messages back for the request. The remote server did complete the three-way TCP connection handshake, but would not acknowledge the request. When I stripped the 'Cache-Control' header using
>
> acl NoCacheCtl dstdomain .epost.go.kr .gtb.go.kr
> header_access Cache-Control deny NoCacheCtl
>
> the TCP ACKs started coming back and we could retrieve content.
>
> My guess is there is a firewall protecting the remote web servers. Has anyone seen this behavior before?

Any cache-control values? or just specific ones?

It's really up to whoever runs the broken software to fix the issue.
Just find out where the breakage is and yell loudly at them.

Amos

--
Please be using
   Current Stable Squid 2.7.STABLE6 or 3.0.STABLE16
   Current Beta Squid 3.1.0.10 or 3.1.0.11