[CentOS] Block network at logoff on workstation

Thu Feb 4 14:19:46 UTC 2010
Ross Walker <rswwalker at gmail.com>

On Feb 3, 2010, at 9:36 PM, David McGuffey <davidmcguffey at verizon.net>  
wrote:

> I'm trying to reduce the attack surface to a home machine that is  
> always
> on and connected to the Internet.  It is running CentOS 5.4, with  
> tight
> iptables rules and sits behind a Verizon FiOS firewall/switch also
> configured with tight rules.
>
> I was wondering how to best block all network access to it when I log
> off...then unblock it when I log on. Changing iptables requires root
> access...as does running ifdown and ifup scripts.
>
> I could change the permissions on ifdown and ifup and run them from  
> the
> login/logout scripts, but I'd prefer not to do that.
>
> Any tips?

Set iptables to block all inbound traffic unless initiated from your  
workstation.

It's the most secure, all the time.

-Ross