[syslog-ng] filter on src ip address.

Hi Guys, I've been looking at syslog-ng's website, but cannot seem to find the correct info. I need to have a syslog server that gather logs from different appliances devices. Currently I just a regular syslogd, the problem is that I need to have every appliance in a different file, and that does syslogd not support. I've looked at the webpage for it appear that syslog-ng support this, I look at the feature list, it says something like this: Filtering for sending IP address, check for syslog-ng. However I have no idea how to configure it or if I misunderstood the meaning of the feature list. Could someone please point me in the correct direction? Cheers Esben