Balagetech has a scintillating article on monitoring traffic with OpenWRT.
The article lays out the process to configure ulog and syslog-ng.
The logs can be sent to an ELK stack for visualization. balagetech.com/monitor-network-traffic-openwrt-syslog-ng/
Crowdsec is a crowd source intrusion prevention system (IPS). Interesting idea, time will tell if it works. They have a Windows agent and a WordPress plugin.
Get more information: crowdstrike.net