Ja - mit folgender pf-Regel:
table <sshattack> persist file "/root/sshattack"
[...]
block in quick from <sshattack> to any
[...]
pass in on $ext_if proto tcp to ($ext_if) port ssh flags S/SA keep state \
(max-src-conn 10, max-src-conn-rate 5/30, overload <sshattack> flush global)
Hier...