How can I block IP address range with sshd_config

[David Keen]

On Wed, 2004-07-28 at 15:23, Matthew Miller wrote:

> I find the tcp wrappers configuration to be more straightforward (and more
> secure) if you change the config to be 'fail-safe' instead of 'fail-open'.
> In other words, put:
> 
>   ALL:ALL
> 
> in hosts.deny, so the default is to block *everything*. Then, explicitly
> turn on the services you want for the source addresses you want:
> 
>   sshd: 192.168.1.      <- or whatever your real allowed subnets are
> 
> or you can do
> 
>   sshd: ALL EXCEPT 211.182.241.
> 
> 
> This way, you never need to track back and forth between hosts.allow and
> hosts.deny, or think about what has precedence, or anything. Simply leave
> only ALL:ALL in hosts.deny, and manage everything in one place.

>From man hosts_options:

The allow and deny keywords make it possible to keep all access control
rules within a single file, for example in the hosts.allow file.
 
       To permit access from specific hosts only:
 
          ALL: .friendly.domain: ALLOW
          ALL: ALL: DENY
                                                                                
       To permit access from all hosts except a few trouble makers:
                                                                                
          ALL: .bad.domain: DENY
          ALL: ALL: ALLOW


-- 
David Keen <zen46443 at zen.co.uk>