How can I block IP address range with sshd_config
David Keen
zen46443 at zen.co.uk
Thu Jul 29 18:13:17 UTC 2004
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>
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