After installing mod_rpaf, I set my config file (/etc/apache2/mods-available/rpaf.conf) as follows:
<IfModule mod_rpaf.c>
RPAFenable On
RPAFsethostname On
RPAFproxy_ips 127.0.0.1
RPAFheader X-Real-IP
</IfModule>
However, now when I restart apache2 I get an error:
Invalid command 'RPAFheader', perhaps misspelled or defined by a module not included in the server configuration
Removing the RPAFheader line resolves the problem, but I really need this setting. Does anyone have any ideas?