indexes:log_format_including_x-forwarding-for [Lnxgeek.org Wiki

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" proxy

SetEnvIf X-Forwarded-For "^.*\..*\..*\..*" forwarded

CustomLog /var/log/apache2/access.log combined env=!forwarded
CustomLog /var/log/apache2/access.log proxy env=forwarded