IPQ BDB is described as 'Filtering is done by a user space netfilter daemon that issues verdicts after looking up the IP address in a Berkeley DB. The fuzzy blocking model, freely inspired by STOCKADE, is designed to block non-distributed dictionary attacks and mitigate spam' and is a Firewall in the security & privacy category. There are more than 10 alternatives to IPQ BDB for Windows, Linux, Web-based and Mac. The best IPQ BDB alternative is Fail2ban, which is both free and Open Source. Other great apps like IPQ BDB are SSHGuard, IPBanPro, Denyhosts and RdpGuard.