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I am having very often internet disconnection problem with Squid proxy service.

My server config;

OS: CentOS release 6.3 (Final)
model name  : Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
cpu MHz     : 1600.000
My Local systems IP range:192.168.2.x 
Server IP:

Also this server is configured with lamp for development,Samba SMB file service manager and No svn currently. So i see maximum possibility is this squid proxy since this is where it stops to connect and am sure when i restart the server net started working so something wrong with this squid service only.

And this server is connected with local 4 other windows machines and basically serves as a central development node.

I am able to resolve it by restarting the server fully some time or sometimes by restarting the squid proxy which is totally killing our development.

Sample error log:

2013/07/01 13:25:38| tunnelConnectTimeout(): tunnelState->servers is NULL
2013/07/01 13:25:41| tunnelConnectTimeout(): tunnelState->servers is NULL
2013/07/01 13:25:41| tunnelConnectTimeout(): tunnelState->servers is NULL
2013/07/01 13:25:50| clientProcessRequest: Invalid Request
2013/07/01 13:26:05| tunnelConnectTimeout(): tunnelState->servers is NULL

Some help can make our lives easier, Thanks in advance.

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I would suspect the lack of connectivity you have is identified by this:

2013/07/01 13:25:38| tunnelConnectTimeout(): tunnelState->servers is NULL

This indicates basically that the connection to the upstream server timed out.

While the problem is happening, try to connect to a few websites on the squid server (use a browser like lynx if you can, but in a pinch you could use telnet to port 80) and see if it times out. If it doesn't, you might have found some kind of bug in squid, but if it does, the problem is upstream of your squid server. Keep an eye out for DNS issues as well.

Also look at increasing your fowarding timeout forward_timeout, particularly if your upstream connection is often slow.

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Am sorry am no super user to do more stuff like this. I just surf through google to fix issues. Let me go from your comments and see what i can do. Thanks a lot for your response. – Ela Jul 1 '13 at 10:35

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