Asterisk 1.8

logpath = /var/log/asterisk/messages

log example:

[Dec 16 23:51:44] NOTICE[8320] chan_sip.c: Registration from '"201" <sip:[email protected]>' failed for '185.28.189.107:5207' - Wrong password

/etc/fail2ban/filter.d/asterisk.conf:

[Definition]
failregex = NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Wrong password
            NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - No matching peer found
            NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Username/auth name mismatch
            NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Device does not match ACL
            NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Peer is not supposed to register
            NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - ACL error (permit/deny)
            NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Device does not match ACL
            NOTICE.* <HOST> failed to authenticate as '.*'$
            NOTICE.* .*: No registration for peer '.*' \(from <HOST>\)
            NOTICE.* .*: Host <HOST> failed MD5 authentication for '.*' (.*)
            NOTICE.* .*: Failed to authenticate user .*@<HOST>.*
            NOTICE.* .*: Sending fake auth rejection for device .*\<sip:.*\@<HOST>\>;tag=.*

/etc/fail2ban/jail.conf

[asterisk-iptables]

enabled  = true
filter   = asterisk
action   = iptables-allports[name=ASTERISK, protocol=all]
           sendmail-whois[name=ASTERISK, dest=root, [email protected]]
logpath  = /var/log/asterisk/messages
maxretry = 5
bantime = 86400