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Alex 'AdUser' Z 5846157eed * update gitignore 7 months ago
configs * tune exec/ipfw backend 7 months ago
contrib * contrib: don't hard depend on mountall 7 years ago
debian * tune debian packaging 1 year ago
docs * make jail filter optional 3 years ago
filters * move filters to their own repository 1 year ago
src * fixes for IPSET_CMD_TEST 1 year ago
t * include some more headers for compatibility 3 years ago
.gitignore * update gitignore 7 months ago
CMakeLists.txt * new version 1 year ago
ChangeLog * new version 1 year ago
Doxyfile * add Doxyfile 8 years ago
LICENSE * apply license 8 years ago * update readme 7 years ago


f2b is lightweight automatic anti-bot turret for your public serivces.


  • written in pure C
  • small memory footprint
  • minimum dependencies (required: libc, libdl; optional: readline, pcre, redis, ipset)
  • fully modular: pluggable sources/filters/backends (you may easy write custom one)
  • support for distributed installs (teamwork)
  • stateful (can save/restore banned ips on restart)
  • adapting to bots (automatically adjust bantime/findtime on rare but steady events from one source)
  • can use not only logfiles, but anything that can give malicious ip: accept(), recv(), pubsub event, pipe
  • may work as honeypot (emulating open tcp ports)


  • Installation -- generic installation instructions
  • Quickstart -- config file description and configuration notes

Similar software:

License: GPL2+