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I am going through an existing HAProxy config file and trying to make sense out of it. I am new to HAProxy. What does the following line do?

reqirep ^Host:\ Host:\

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up vote 1 down vote accepted

It replaces lines matching Host: with Host: in the HTTP header in a case insensitive way. See also the documentation.

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Thanks for that. When would this be done, when the request comes in or goes out? Also, any idea why would someone what to do something like this? – foobarmoo Nov 14 '12 at 13:32
It is done only on request headers that come in and will be forwarded by haproxy. As to why someone would want that: some servers refuse requests containing a Host: XXX headers where they don't recognize XXX. If the server cannot be fixed, an haproxy workaround may work. – Dennis Kaarsemaker Nov 14 '12 at 13:56

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