[squid-users] TCP_MISS/502

Amos Jeffries squid3 at treenet.co.nz
Tue Nov 17 21:05:23 UTC 2015

On 18/11/2015 3:07 a.m., Ачилов Рашид Нурмухамедович wrote:
> How do you do.
> When accessing to site http://www.ycmcnc.com through Squid 3.5.x (tried
> 3.5.2 and 3.5.11) immediately at first try occured TCP_MISS/502:
> 1447767437.903    585 TCP_MISS/502 4267 GET
> http://www.ycmcnc.com/ - HIER_DIRECT/ text/html
> When tried access without proxy all OK. When tried access with old Squid
> 2.7-STABLE9 all OK. Troubles occured when tried through Squid 3.5.x.

The server PHP scripts are apparently crashing whenever it receives the
*valid* X-Forwarded-For header of the type which gets emitted when you

> forwarded_for off

I can also reproduce the same crash/terminate behaviour when most other
perfectly valid XFF header are sent. The web developer who authored that
site is very ignorant of how X-Forwarded-For is used.

To work around this either remove the forwarded_for directive
completely. Or set it to another value than "off".
see <http://www.squid-cache.org/Doc/config/forwarded_for/>

Given the set of things that cause the server to die. You are probably
best going with truncate or delete.


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