- http://www.rsyslog.com/doc/rsconf1_allowedsender.html
- http://www.rsyslog.com/storing-messages-from-a-remote-system-into-a-specific-file/
- https://doc.pfsense.org/index.php/Copying_Logs_to_a_Remote_Host_with_Syslog
- https://devops.profitbricks.com/tutorials/configure-remote-logging-with-rsyslog/