[PLUG] SSH in general from: Re: Pros and cons of key-pair based vs passw

[PLUG] SSH in general from: Re: Pros and cons of key-pair based vs password based SSH...

I recently allowed a port for ssh (default settings) on my machine/router so a friend could try and connect to it.

Within days someone tried to log on to my machine over 30,000 times in about one hours time.

What I found surprising was that ssh by default did not recognized this rapid fire attempt to log on my machine and create some sort of delay between each attempt.

I guess all the configurations that have been written about recently help prevent such password guessing games. I guess they eliminate the idea of an unknown machine trying to log on. If possible at all, do they limit the number of times an unauthorized person can try to log on?

Having seen the attempts to log into my machine, I learned there are ways with iptables and I think ssh itself (recent discussion at a PLUG meeting) to cause it to delay some time after a few attempted logins. So that if someone tries unsuccessfully to log in say 10 times, a delay will be created to force a one minute wait time before the next attempt.

Edmond
From: Fred Stluka <fred@bristle.com>
To: Philadelphia Linux User's Group Discussion List <plug@lists.phillylinux.org>
Sent: Thursday, June 11, 2009 5:47:50 PM
Subject: Re: [PLUG] Pros and cons of key-pair based vs password based
 SSH...

        Thanks for all the great suggestions everyone!  I've followed a 
 bunch of the links you sent, read the man page for ssh_config
 and sshd_config, and made some changes.  I especially like the 
 idea of limiting which users can login via AllowUsers and/or 
 AllowGroups.  OpenSSH has a ton of features.  I had no idea about 
 the possibility of sharing access to the same connection to get 
 remote filename completion on scp, etc.  Cool!
  --Fred
---------------------------------------------------------------------
Fred Stluka -- mailto:fred@bristle.com -- http://bristle.com/~fred/
Bristle Software, Inc -- http://bristle.com -- Glad to be of service!
---------------------------------------------------------------------
 
 
 Michael Bevilacqua wrote: On Wed, Jun 10, 2009 at 8:42 PM, Richard Freeman <r-plug@thefreemanclan.net> wrote:
The other thing I do is to modify my pam config for ssh to only allow
 particular accounts to log in
 Note that, if you have access to /etc/ssh/sshd_config you could simply use this configuration option:
   
 AllowUsers user1 user2 user3
   
 See sshd_config(5) for more details on this option.
   
 
  

 -- 
 Michael D. Bevilacqua
michael@bevilacqua.us
 ___________________________________________________________________________ Philadelphia Linux Users Group         --        http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug    