New blog post: GeoIP-Aware Firewalling with PF on FreeBSD
Running a mail server means constant brute-force attempts. My solution: geographic filtering. SMTP stays open for global mail delivery, but client ports (IMAP, Submission, webmail) are restricted to Central European IP ranges only.
Result: ~90% reduction in attack logs, cleaner signal-to-noise ratio, smaller attack surface.
Using MaxMind GeoLite2 + PF tables with ~273k CIDR blocks.
https://blog.hofstede.it/geoip-aware-firewalling-with-pf-on-freebsd/