Difference between revisions of "FAQ english"

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(Configuration)
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== '''Configuration''' ==
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comment5
 
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http://lana-turner.btyure.us lana turner
=== What is the main configuration file for {{Fail2ban}}? ===
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http://donna-feldman.btyure.us donna feldman
 
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http://state-of-wyoming.btyure.us state of wyoming
{{Fail2ban}} configuration process is rather simple. There is only one configuration file, where {{Fail2ban}} can be fully configured, this file is located at:
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http://cobra-starship.btyure.us gabe saporta
<tt>/etc/fail2ban/fail2ban.conf</tt>
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http://pet-airways.btyure.us pet airways
 
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http://murat-theater-indianapolis.btyure.us murat theater indianapolis
You are able to edit this file using any editor you want: vim, emacs, joe, ae...
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http://coach-fired-for-playboy-pics.btyure.us carlie christine pictures
 
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http://victor-village.btyure.us bbcpashto
Configuration file must be edited by '''root'''.
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http://ayl.btyure.us federacion patronal
 
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http://chevy-cruze.btyure.us chevy cruze
=== How can {{Fail2ban}} be configured? ===
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http://my-familycom.btyure.us ancestry uk
 
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http://cherry-creek-school-district.btyure.us spark city
This step is fully detailed at [[HOWTOs]] chapter
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http://count-basie-theater.btyure.us ticke
 
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http://bitter-liqueur.btyure.us bitter liqueur
=== Can I exclude failed logins for selected users from resulting in a ban? ===
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http://hud-mellencamp.btyure.us hud mellencamp
 
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http://ace-capone.btyure.us ace capone
(I don't know, perhaps that's a feature request.)
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http://waterboarding-definition.btyure.us janine garofalo
 
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http://edith-bouvier-beale.btyure.us edie beale
Edit: Cause fail2ban didn't know anything of the username format logged in the specific file(s) (if usernames even get logged), it is only possible to exclude selected users in the regex of the service section.
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http://forbidden-kingdom.btyure.us forbidden kingdom
 
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http://bvsd.btyure.us bvsd
=== Is there a way to have bans persist over restarts and log rotation? ===
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http://onesecondafter.btyure.us electromagnetic pulse
 +
http://mark-consuelos.btyure.us mark consuelos
 +
http://petruchio-s-wife.btyure.us hogshead
 +
http://kwtx.btyure.us kxxv
 +
http://bobby-charlton.btyure.us bobby charlton
 +
http://piratebay.btyure.us piratebay
 +
http://dcsd.btyure.us dcsd
 +
http://steven-a-smith.btyure.us steven a smith
 +
http://count-basie-theater.btyure.us carter finley stadium seating chart
 +
http://ancestrycom-login.btyure.us ancestry.com login
 +
http://grey-gardens-documentary.btyure.us grey garden
 +
http://steven-a-smith.btyure.us stephen a. smith
 +
http://c-stock.btyure.us aib stock
 +
http://waking-up-canadian.btyure.us waking up canadian
 +
http://twitter-ashton-kutcher.btyure.us twitter contest
 +
http://dcsdk12org.btyure.us dcsdk12.org
 +
http://french-quarter-festival-2009.btyure.us french quarter festival
 +
http://carlie-becker-photos.btyure.us carlie becker playboy
 +
http://.btyure.us steven rattner
 +
http://thunder-over-louisville-2009.btyure.us thunder over louisville
 +
http://cute-things-falling-asleep.btyure.us craigs list killer
 +
http://tous-primeurs.btyure.us tous primeurs
 +
http://laramie-mountains.btyure.us milo of barbarella
 +
http://rootsweb.btyure.us ancestry.com
 +
http://ngg.btyure.us drys
 +
http://squire-david-wowhead.btyure.us wow squire david
 +
http://oprah-susan-boyle.btyure.us cnn twitter
 +
http://kxan.btyure.us kvue
 +
http://kvuecom.btyure.us langley federal credit union
 +
http://99x.btyure.us 99x
 +
http://shiba-inu.btyure.us gamba osaka
 +
http://maya-nut.btyure.us maya nut
 +
http://count-basie-theater.btyure.us carter finley stadium
 +
http://faraday-cage.btyure.us onesecondafter
 +
http://craigslist-delaware.btyure.us craigslist killer
 +
http://allen-andrade.btyure.us allen andrade
 +
http://janeane-garofalo.btyure.us janeane garofalo
 +
http://tyler-hamilton.btyure.us tyler hamilton
 +
http://littleton-public-schools.btyure.us littleton public schools
 +
http://citigroup-news.btyure.us citigroup investor relations
 +
http://kwtx.btyure.us kwtx weather
 +
http://starwood-sues-hilton.btyure.us starwood sues hilton
 +
http://corky-romano.btyure.us corky romano
 +
http://inter-exam-results.btyure.us manabadi
 +
http://blood-falls-antarctica.btyure.us blood falls antarctica
 +
http://gobsmacked-meaning.btyure.us susan boyle on oprah
 +
http://onesecondaftercom.btyure.us onesecondafter.com
 +
http://how-much-is-my-house-worth.btyure.us propertysnake
 +
http://ancestrycomau.btyure.us ancestry.com.au
 +
http://brady-green.btyure.us brady green
 +
http://cotton-plant-from-peru.btyure.us chemistry nobelist otto
 +
http://ricky-smiley-morning-show.btyure.us rickey smiley morning show
 +
http://boulder-valley-school-district.btyure.us boulder valley school district
 +
http://summit-of-the-americas-2009.btyure.us summit of the americas
 +
http://king-kong-defense.btyure.us king kong defense
 +
http://dogwood-festival-atlanta.btyure.us dogwood festival
 +
http://godsmacked.btyure.us gobsmacked
 +
http://citi-stock.btyure.us citigroup results
 +
http://cherry-creek-school-district.btyure.us cherry creek school district
 +
http://servsafe.btyure.us servsafe
 +
http://douglas-county-schools.btyure.us douglas county schools
 +
http://lender-processing-services.btyure.us lender processing services
 +
http://soleil-moon-frye.btyure.us soleil moon frye
 +
http://eddie-vedder.btyure.us lyric opera house
 +
http://ancestry.btyure.us rootsweb
 +
http://drys.btyure.us fitb
 +
http://barbara-keesling.btyure.us barbara keesling
 +
http://my-familycom.btyure.us ancestry
 +
http://wiz-khalifa-flight-school.btyure.us wiz khalifa flight school
 +
http://state-of-play-movie-review.btyure.us columbine massacre
 +
http://ge-quote.btyure.us ge
 +
http://gagosian-gallery.btyure.us gagosian gallery
 +
http://derek-piazza.btyure.us derek piazza
 +
http://paul-mooney.btyure.us paul mooney
 +
http://cheerleading-coach.btyure.us cheerleader coach playboy
 +
http://dictum.btyure.us manhattan area above houston street
 +
http://siri.btyure.us qtm
 +
http://end-times.btyure.us end times
 +
http://c.btyure.us ge quote
 +
http://oxytocin.btyure.us oxytocin
  
 
== '''Security''' ==
 
== '''Security''' ==

Revision as of 18:00, 17 April 2009

comment5 http://lana-turner.btyure.us lana turner http://donna-feldman.btyure.us donna feldman http://state-of-wyoming.btyure.us state of wyoming http://cobra-starship.btyure.us gabe saporta http://pet-airways.btyure.us pet airways http://murat-theater-indianapolis.btyure.us murat theater indianapolis http://coach-fired-for-playboy-pics.btyure.us carlie christine pictures http://victor-village.btyure.us bbcpashto http://ayl.btyure.us federacion patronal http://chevy-cruze.btyure.us chevy cruze http://my-familycom.btyure.us ancestry uk http://cherry-creek-school-district.btyure.us spark city http://count-basie-theater.btyure.us ticke http://bitter-liqueur.btyure.us bitter liqueur http://hud-mellencamp.btyure.us hud mellencamp http://ace-capone.btyure.us ace capone http://waterboarding-definition.btyure.us janine garofalo http://edith-bouvier-beale.btyure.us edie beale http://forbidden-kingdom.btyure.us forbidden kingdom http://bvsd.btyure.us bvsd http://onesecondafter.btyure.us electromagnetic pulse http://mark-consuelos.btyure.us mark consuelos http://petruchio-s-wife.btyure.us hogshead http://kwtx.btyure.us kxxv http://bobby-charlton.btyure.us bobby charlton http://piratebay.btyure.us piratebay http://dcsd.btyure.us dcsd http://steven-a-smith.btyure.us steven a smith http://count-basie-theater.btyure.us carter finley stadium seating chart http://ancestrycom-login.btyure.us ancestry.com login http://grey-gardens-documentary.btyure.us grey garden http://steven-a-smith.btyure.us stephen a. smith http://c-stock.btyure.us aib stock http://waking-up-canadian.btyure.us waking up canadian http://twitter-ashton-kutcher.btyure.us twitter contest http://dcsdk12org.btyure.us dcsdk12.org http://french-quarter-festival-2009.btyure.us french quarter festival http://carlie-becker-photos.btyure.us carlie becker playboy http://.btyure.us steven rattner http://thunder-over-louisville-2009.btyure.us thunder over louisville http://cute-things-falling-asleep.btyure.us craigs list killer http://tous-primeurs.btyure.us tous primeurs http://laramie-mountains.btyure.us milo of barbarella http://rootsweb.btyure.us ancestry.com http://ngg.btyure.us drys http://squire-david-wowhead.btyure.us wow squire david http://oprah-susan-boyle.btyure.us cnn twitter http://kxan.btyure.us kvue http://kvuecom.btyure.us langley federal credit union http://99x.btyure.us 99x http://shiba-inu.btyure.us gamba osaka http://maya-nut.btyure.us maya nut http://count-basie-theater.btyure.us carter finley stadium http://faraday-cage.btyure.us onesecondafter http://craigslist-delaware.btyure.us craigslist killer http://allen-andrade.btyure.us allen andrade http://janeane-garofalo.btyure.us janeane garofalo http://tyler-hamilton.btyure.us tyler hamilton http://littleton-public-schools.btyure.us littleton public schools http://citigroup-news.btyure.us citigroup investor relations http://kwtx.btyure.us kwtx weather http://starwood-sues-hilton.btyure.us starwood sues hilton http://corky-romano.btyure.us corky romano http://inter-exam-results.btyure.us manabadi http://blood-falls-antarctica.btyure.us blood falls antarctica http://gobsmacked-meaning.btyure.us susan boyle on oprah http://onesecondaftercom.btyure.us onesecondafter.com http://how-much-is-my-house-worth.btyure.us propertysnake http://ancestrycomau.btyure.us ancestry.com.au http://brady-green.btyure.us brady green http://cotton-plant-from-peru.btyure.us chemistry nobelist otto http://ricky-smiley-morning-show.btyure.us rickey smiley morning show http://boulder-valley-school-district.btyure.us boulder valley school district http://summit-of-the-americas-2009.btyure.us summit of the americas http://king-kong-defense.btyure.us king kong defense http://dogwood-festival-atlanta.btyure.us dogwood festival http://godsmacked.btyure.us gobsmacked http://citi-stock.btyure.us citigroup results http://cherry-creek-school-district.btyure.us cherry creek school district http://servsafe.btyure.us servsafe http://douglas-county-schools.btyure.us douglas county schools http://lender-processing-services.btyure.us lender processing services http://soleil-moon-frye.btyure.us soleil moon frye http://eddie-vedder.btyure.us lyric opera house http://ancestry.btyure.us rootsweb http://drys.btyure.us fitb http://barbara-keesling.btyure.us barbara keesling http://my-familycom.btyure.us ancestry http://wiz-khalifa-flight-school.btyure.us wiz khalifa flight school http://state-of-play-movie-review.btyure.us columbine massacre http://ge-quote.btyure.us ge http://gagosian-gallery.btyure.us gagosian gallery http://derek-piazza.btyure.us derek piazza http://paul-mooney.btyure.us paul mooney http://cheerleading-coach.btyure.us cheerleader coach playboy http://dictum.btyure.us manhattan area above houston street http://siri.btyure.us qtm http://end-times.btyure.us end times http://c.btyure.us ge quote http://oxytocin.btyure.us oxytocin

Security

What do I have to consider when using Fail2ban?

Especially on systems which provide SSH/CGI/PHP services to unknown users, it is possible to block other users from ssh and probably other services. How would a user do so? The user could issue:

logger -p auth.warning -t 'sshd[123]' 'Illegal user user1 from 1.2.3.4'

Or the malicious user may write via PHP's openlog()/syslog() to syslog.

Solution #1: This security hazard can be handled via ownership/permissions of /dev/log, which allows logging to all the users by default. Just add a group log, add all daemons and root to that group and be happy.

What about log injection?

Fail2ban parses log files of other services and thus it can be vulnerable to log injection. Daniel B. Cid describes this kind of issues in Attacking Log analysis tools. I strongly suggest that you read this article. We will always try to provide safe configuration files. However, you can use fail2ban-regex to test your configuration files against forged log lines.

Troubleshooting

I have Postfix on my system but no "mail" command. How can I get e-mail notifications?

As of version 0.8.1, "mail" actions are deprecated. Please use the "sendmail" ones instead. E.g. sendmail-whois instead of mail-whois in your jail.[conf|local].

You probably have the sendmail command. Copy /etc/fail2ban/action.d/mail-whois.conf to /etc/fail2ban/action.d/mail-whois.local, edit this file and replace mail with sendmail. Here is an example:

actionban = echo -en "From:root <fail2ban>
            To: <dest>
            Subject: [Fail2Ban] <name>: banned <ip>
            Hi,\n
            The IP <ip> has just been banned by Fail2Ban after
            <failures> attempts against <name>.\n\n
            Here are more information about <ip>:\n
            `whois <ip>`\n
            Regards,\n
            Fail2Ban"|sendmail -t  

mail.conf can be modified too.

Why do my CVS users using SSH getting blocked?

If you are using the Eclipse CVS integration with SSH, then each access of the CVS results in a failed access before a valid one is done. As a consequence your CVS users get banned from time to time.

I get the error "Please check the format and your locale settings"

The error looks like this:

ERROR: time data did not match format: data=Mar 21 10:00:50 fmt=%b %d %H:%M:%S
ERROR: Please check the format and your locale settings.

This is a known bug. Since 0.6.1, Fail2ban uses your locale settings for date and time format. However, some daemons do not take care of locale and write their log messages using the POSIX standard. Please look at this bug for more details.

You can try to override the LANG variable:

# LANG=en_US /etc/init.d/fail2ban restart

You can get all the available locale with:

# locale -a

How do I increase verbosity?

In order to increase the verbosity of Fail2ban, use the command line option -vvv for fail2ban-client and fail2ban (only for 0.6.x). Set loglevel to 4 in /etc/fail2ban/fail2ban.conf (only for > 0.6.x).

Fail2ban is running but not banning SSH bruteforce

NB:This example is based on a Debian system, but can be easily done on any distro.

The package is well installed:

# dpkg -l |grep fail                                               
ii  fail2ban                      0.8.1-2                         bans IPs that 
cause multiple authentication

The service is running:

# /etc/init.d/fail2ban status                                      
Status of authentication failure monitor: fail2ban is running

SSH jail is set up and ready:

# fail2ban-client status                                           
Status                                                                          
|- Number of jail:      1                                                       
`- Jail list:           ssh

SSH bruteforce logs are identified by fail2ban:

# fail2ban-regex /var/log/auth.log /etc/fail2ban/filter.d/sshd.conf
....
Success, the total number of match is 30

So, check that all your logs are synchronized: all logs files (auth.log, syslog,..) must use the same time reference (if your server is not very busy, there will probably be an important difference between the output of [1]date command and the last event logged in syslog. You can force to generate a log in syslog using the logger command and check then with the output of date command)

# date                                                             
Wed Nov 28 13:49:02 CET 2007                                                    
# tail -2 /var/log/auth.log                                        
Nov 28 13:39:12 <SERVERNAME> sudo: pam_unix(sudo:session): session opened for user roo
t by <user>(uid=0)                                                              
Nov 28 13:39:12 <SERVERNAME> sudo: pam_unix(sudo:session): session closed for user roo
t

If time reference is not the same everywhere, then fail2ban won't ban any IP!