• Trusted IP for which X-Forwarded-For is acceptable: IP/Block IP/FQDN

These directives list the IP address from which Vulture will trust the X-FORWARDED-FOR header.
It is used for example when Haproxy is configured and load balance web traffic to the Vulture cluster.
Haproxy creates an X-FORWARDED-FOR header in the HTTP request, with the REMOTE_ADDR value.

By default, if Vulture sees a X-FORWARDED-FOR header coming from itself or an other member of the cluster, it will replace the REMOTE_ADDR header with it.
So if you have a proxy ahead, you'll need to specify its IP address to accept the X-FORWARDED-FOR header.