guido

Remove IP it’s a really-really-simple plugin to not log the IP address from the people that comment on your wordpress 
installation.
This plugin will be useful to people that cannot/or don’t want to use <a href="http://riseuplabs.org/privacy/apache/" title="libapache2-mod-removeip" rel="nofollow ugc">libapache2-mod-removeip</a> (because you don’t use 
apache or don’t want to wipe out the IP logging on all vhosts).

Remove IP

The plugin does exactly what its name suggests: it removes the IP address from new comments on your blog – not more and not less.

Simple and efficient

A simple plugin to not log IPs from comments.

Masoud Binaei

This plugin allow WordPress to detect Real visitors IP Address when WordPress is behind of Reverse Proxy, Load Balancer or CDN. 
It will start working as soon as you activate it.
It is also compatible:
<ul>
<li>Cloudflare.com</li>
<li>geniusguard.com</li>
<li>central-hosting.com</li>
<li>incapsula.com</li>
<li>sucuri.net</li>
<li>barracuda.com</li>
<li>f5.com And Other…</li>
</ul>

Real IP Detector

Very good

This plugin allow WordPress to detect Real visitors IP Address.

Remove IP vs Real IP Detector