Forwarded to devs FAIL2BAN issue when IPv6 enabled

[virtubox]

TITLE:

FAIL2BAN issue when IPv6 enabled​

PRODUCT, VERSION, OPERATING SYSTEM, ARCHITECTURE:

Ubuntu 16.04.3 LTS
Plesk Onyx 17.8.9​

PROBLEM DESCRIPTION:

When IPv6 is enabled on the server, Fail2ban add the server IPv6 address in its whitelist and fail to start.
I have noticed this issues because there wasn't any IP banned for few weeks​

STEPS TO REPRODUCE:

• Make a clean install of Plesk Onyx on a server with IPv6 enabled
• Install and enable fail2ban

ACTUAL RESULT:

Fail2ban isn't able to start and server isn't protected against bruteforce

2018-02-04 06:30:02,797 fail2ban.filter [1838]: WARNING Unable to find a corresponding IP address for 2001:XXXX:XXXX:XXXX::XXXX: [Errno -9] Address family for hostname not supported

EXPECTED RESULT:

Fail2ban start properly

Few minutes after removing the IPv6 of the address whitelist :

2018-02-08 11:21:38,985 fail2ban.filter [1838]: INFO Set maxRetry = 5
2018-02-08 11:21:38,986 fail2ban.filter [1838]: INFO Set findtime = 600
2018-02-08 11:21:38,986 fail2ban.actions [1838]: INFO Set banTime = 600
2018-02-08 11:21:38,990 fail2ban.jail [1838]: INFO Jail 'ssh' started
2018-02-08 11:21:38,992 fail2ban.jail [1838]: INFO Jail 'recidive' started
2018-02-08 11:21:38,997 fail2ban.jail [1838]: INFO Jail 'plesk-proftpd' started
2018-02-08 11:21:39,008 fail2ban.jail [1838]: INFO Jail 'plesk-postfix' started
2018-02-08 11:21:39,016 fail2ban.jail [1838]: INFO Jail 'plesk-dovecot' started
2018-02-08 11:21:39,020 fail2ban.jail [1838]: INFO Jail 'plesk-horde' started
2018-02-08 11:21:39,022 fail2ban.jail [1838]: INFO Jail 'plesk-roundcube' started
2018-02-08 11:21:39,023 fail2ban.jail [1838]: INFO Jail 'plesk-apache' started
2018-02-08 11:21:39,026 fail2ban.jail [1838]: INFO Jail 'plesk-apache-badbot' started
2018-02-08 11:21:39,028 fail2ban.jail [1838]: INFO Jail 'plesk-panel' started
2018-02-08 11:21:39,030 fail2ban.jail [1838]: INFO Jail 'plesk-wordpress' started
2018-02-08 11:22:55,342 fail2ban.filter [1838]: INFO [plesk-postfix] Found 80.XXX.70.XXX
2018-02-08 11:23:22,665 fail2ban.filter [1838]: INFO [plesk-postfix] Found 191.96.XXX.XXX
2018-02-08 11:24:35,136 fail2ban.filter [1838]: INFO [plesk-postfix] Found 91.XXX.12.XXX
2018-02-08 11:25:58,593 fail2ban.filter [1838]: INFO [plesk-postfix] Found 91.XXX.12.232
2018-02-08 11:28:08,138 fail2ban.filter [1838]: INFO [plesk-postfix] Found 191.96.XXX.XXX
2018-02-08 11:29:29,352 fail2ban.filter [1838]: INFO [plesk-postfix] Found 91.XXX.12.XXX
2018-02-08 11:30:41,221 fail2ban.filter [1838]: INFO [plesk-postfix] Found 91.XXX.12.XXX
2018-02-08 11:30:41,378 fail2ban.filter [1838]: INFO [plesk-postfix] Found 91.XXX.12.XXX

ANY ADDITIONAL INFORMATION:

​

YOUR EXPECTATIONS FROM PLESK SERVICE TEAM:

Confirm bug​