blog.kempkens.io/content/posts/2016-01-31-anonymizing-ips-using-haproxy.md

date	description	tags	slug	title
2016-01-31T17:46:00Z	Description of how to easily anonymize IPs using HAProxy.	haproxy ops english	anonymizing-ips-using-haproxy	Anonymizing IPs Using HAProxy

At work, I had to come up with an easy way to anonymize the last octet of a logged IP address in order to comply with German data protection laws. If you're using HAProxy (1.5+), you can do this in one line.

If you want to forward the source IP address to a backend server, you would usually use option forwardfor. Sadly you can't set or change the forwarded IP using that option, so instead you have to set the X-Forwarded-For header manually.

{{< highlight text >}} http-request set-header X-Forwarded-For %[src,ipmask(24)] {{< / highlight >}}

This will set the last octet of the source IP address to zero.

The HAProxy documentation has more information on the various things I used in this post:

• option forwardfor
• http-request
• src sample
• ipmask converter