USR-Guard acts as a bridge between Snort and a US Robotics 9105 ADSL router. When a snort alert is generated, USR-Guard will connect into your US Robotics router and add rules to block the host. This block is then removed after a defined period of hours.
You can download it from the following link: https://packetstormsecurity.com/files/download/36263/usr-guard-1.0.bz2
Source: https://packetstormsecurity.com/files/36263/usr-guard-1.0.bz2.html