@kwangmien There is a section in this forum for IDS/IPS where you find all you need on Suricata and Snort. Then there is another package called pfBlockerNG which I guess is what you might be thinking of as web filter.
https://forum.netgate.com/category/53/ids-ips
https://forum.netgate.com/category/62/pfblockerng
No software licenses required and there are both free and paid versions of the rulesets used. And for pfblocker you would benefit from getting a MaxMind license, also free.