This is a pretty broad request. It sounds like what you are wanting is something like Netflow to Syslog or a Netflow collector that can alert on specific events and send the event as Syslog. Also when I say Netflow, I am including other similar protocols like sFlow and jFlow in that umbrella term.
SolarWinds does have a Netflow product which does have alerting and reporting, etc. You can see that here.
Another option is you can use an open-source NetFlow collector that supports syslog. NTop is an example of such a collector. You can set that up to send Syslog with ex. commands below
- ntop --daemon --use-syslog
- ntop --deamon --use-syslog=local3