Attacks on ssh port

[Willem Jan Withagen]

David D.W. Downey wrote:

>On Sat, 18 Sep 2004 14:18:32 +0200, Willem Jan Withagen <wjw at withagen.nl> wrote:
>  
>
>>Hi,
>>
>>Is there a security problem with ssh that I've missed???
>>Ik keep getting these hords of:
>>    Failed password for root from 69.242.5.195 port 39239 ssh2
>>with all kinds of different source addresses.
>>
>>They have a shot or 15 and then they are of again, but a little later on
>>they're back and keep clogging my logs.
>>Is there a "easy" way of getting these ip-numbers added to the
>>blocking-list of ipfw??
>>
>>Thanx,
>>--WjW
>>    
>>
>
>well you want to see those. So long as you have
>
>PermitRootLogin no
>
>in your /etc/ssh/sshd_config, they won't be able to get in since ssh
>is then denied for root (except via a valid ssh key which you can
>further lock down by adding
>
>from="ip.addr, forward.dns.record.of.host" 
>
>to the beginning of your ssh-dsa or ssh-rsa key line in ~/.ssh/authorized_keys)
>
>  
>
It is not about all this. I know these, and I use them if appropriate.
(Come to think of it, I was one of the first externals to test Wietse 
Venema's TCP-wrapper.)

Once I have identified the nature and quality of  this type of problem, 
I want to deal with it in such a way that it is no longer a bother. And 
in this particular case these records are clogging my login error 
records. And because of that I just might miss out on the one or two 
that do matter. You might want to call it noise-reduction, and I'm 
looking for a as large as possible Signal/Noise ratio.
So that is why I would like to be able to throw root/ssh login attempts 
directly in the garbage and kill the host where these are coming from 
with a records in my firewall.

--WjW