Question

I have a server running Ubuntu 12.04 LTS, Pound 2.6 and Apache 2.2. I have also the apache module mod_rpaf (installed from https://github.com/gnif/mod_rpaf) installed and enabled to ensure, that in the variable REMOTE_ADDR appears the real user ip address and not the address of the proxy.
This works fine, but the variable REMOTE_HOST is not changed by mod_rpaf. This variable contains “localhost” and not the host of the given user ip address.

Can you help me, please?

Here is my mod_rpaf configuration:

root@perseus ~ # cat /etc/apache2/mods-enabled/rpaf.conf 
RPAF_Enable       On
RPAF_ProxyIPs     127.0.0.1
RPAF_Header       X-Forwarded-For
RPAF_SetHostName  On
RPAF_SetHTTPS     On
RPAF_SetPort      On

Thank you

Answer 1

Check theses answers on a previous question about a missing REMOTE_HOST:

REMOTE_HOSTS is a variable that may or may not be populated by apache (and it’s better if it is not set, else it imply a DNS query by apache for every incoming request). So Nothing on your code should rely on REMOTE_HOST. No application should assume this variable will be there and correctly filled.

mod_rpaf does what it is designed for, documentation:

Sets REMOTE_ADDR, HTTPS, and HTTP_PORT to the values provided by an upstream proxy.

Now you have a working REMOTE_ADDR, which is the only variable you should trust, make a copy of it in REMOTE_HOST if you really wants that, and simply do it in your application code.