[179758] in North American Network Operators' Group
Re: Network Segmentation Approaches
daemon@ATHENA.MIT.EDU (Andrew Jones)
Wed May 6 19:09:10 2015
X-Original-To: nanog@nanog.org
Date: Thu, 07 May 2015 09:08:38 +1000
From: Andrew Jones <aj@jonesy.com.au>
To: <nanog@nanog.org>
In-Reply-To: <20150506153001.C491D9D8@m0048141.ppops.net>
Errors-To: nanog-bounces@nanog.org
It depends on the software used and implementation.
Many rulesets for pf on BSD start with 'block in on interfaceX' for
instance, because it uses a "last match wins" system, unless you use the
'quick' keyword to make rule processing stop if that rule matches.
Andrew
On 07.05.2015 08:30, Scott Weeks wrote:
> --- rsk@gsp.org wrote:
> From: Rich Kulawiec <rsk@gsp.org>
>
> The first rule in every firewall is of course
> "deny all" and subsequent rulesets permit only
> the traffic that is necessary.
> ------------------------------------
>
>
> I think you got this backward? That way all
> traffic is blocked, so none is allowed through.
> Also, deny by default at the end of the rule
> set is not the best thing for every network
> that needs a firewall. Some just want to block
> bad stuff they see and allow everything else.
> (And some have stated here that they will block
> entire countries until their culture changes!)
>
> scott
