Asterisk 11 (FreePBX distribution) fail2ban configuration using the security log.

I’ve been experimenting with Asterisk again, using the FreePBX distro (2.11.0.4). I have noticed that I get a lot of entries in the Asterisk log that look like this: [2013-07-06 05:11:06] NOTICE[4106][C-0000001f] chan_sip.c: Failed to authenticate device 555<sip:555@aaa.bb.ccc.dd>;tag=e9a98a30 [2013-07-06 05:11:08] NOTICE[4106][C-00000020] chan_sip.c: Failed to authenticate device 555<sip:555@aaa.bb.ccc.dd>;tag=eebd8857 [2013-07-06 05:11:12] NOTICE[4106][C-00000021] chan_sip.c: Failed to authenticate device […]