[syslog-ng]testing from a remote server

I have syslog-ng running, and it logs everything from the server it runs on. How can I test to make sure it logs from remote sources. I'm kind of new to syslog-ng. My server listens to UDP 514, and allows it through the firewall. I have 2 devices I really want to have log to it. A Cisco Aironet 1100, and a symantec firewall device we use on our back up connection. How can I test to make sure syslog-ng is capturing what I'd like it to. -Mike