Here is an example of a simple but effective blacklist system that I’m using on my pfSense firewalls. pfSense is a very modular firewall that can be expanded with many packages. About blacklists, there is a well-known one called pfBlocklist. Personally, I prefer to avoid installing extra packages on my firewalls because it increases the risk to face potential problems while upgrading (pfSense recommends to disable them before any upgrade). Some packages might also be developed by 3rd parties that have a light security mindset and, therefore, introduce bugs in a core element of the infrastructure.
Article Link: https://isc.sans.edu/diary/rss/26380