Quickly ban an IP IPFW?

[Andreas X]

I have IPFW enabled like follows:

firewall_enable="YES"
firewall_quiet="YES"
firewall_type="workstation"
firewall_logdeny="NO"
firewall_allowservices="any"
firewall_myservices="53/tcp 53/udp 10025/tcp 10024/tcp 25/tcp 993/tcp
995/tcp 465/tcp 587/tcp 5665/tcp 80/tcp 443/tcp 2053/tcp 3306/tcp"

(No rules file, the ones above suits my needs perfectly)

How to quickly (and permanently) ban an IP using IPFW without having any
log?

There's an IP address scanning almost all my services 24/7, would like to
permanently ban.

Thanks.