[asterisk-users] sip extension compromised, need help blocking brute force attempts

[David Backeberg]

On Mon, Jun 30, 2008 at 5:10 PM, Kristian Kielhofner
<kkielhofner at star2star.com> wrote:
>  Does anyone want to write a kernel module? ;)

The thing I was mentioning about hashing addresses is already in the
kernel, check out:
hashlimit on google,
or net/netfilter/xt_hashlimit.c in your favorite 2.6 kernel source

The other cases you mention could be done with multiple rules,
especially if you know good subnets / netmasks.