[syslog-ng] organizing logs over network

if i use source-> system(facility(local0)); and use an application that sends to local0, what's the most effective way of categorizing this into a special log file if the destination is over network? I'm using two dns machines and they both send output to one logging machine. So far I'm using the host() directive with filter{} and two log{} entries on the recipient, this way I can create a log depending on the ip. Is there a better way to organize the logs instead of using host() with filter{} ? thanks