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Date:      Sat, 21 Jul 2012 14:58:03 +0100
From:      Greg Hennessy <Greg.Hennessy@nviz.net>
To:        "Tonix (Antonio Nati)" <tonix@interazioni.it>
Cc:        "freebsd-pf@freebsd.org" <freebsd-pf@freebsd.org>
Subject:   RE: Question on packet filter using in and out interfaces
Message-ID:  <9EB23F6C23A8B6488E8BCC92A48E83264BB4D27241@PEMEXMBXVS04.jellyfishnet.co.uk.local>
In-Reply-To: <500AB340.2040405@interazioni.it>
References:  <500826BD.3070602@interazioni.it> <9EB23F6C23A8B6488E8BCC92A48E83264BB4D26F80@PEMEXMBXVS04.jellyfishnet.co.uk.local> <500AB340.2040405@interazioni.it>

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As I recall there is a diagram out there which detail the packet flow start=
ing with the ingress interface.

It'll explain what gets evaluated where. Bear in mind the effect of the 'qu=
ick' keyword. Something I tend to always use.=20

Regards

Greg


> -----Original Message-----
> From: Tonix (Antonio Nati) [mailto:tonix@interazioni.it]
> Sent: Saturday, 21 July 2012 11:49 PM
> To: Greg Hennessy
> Cc: freebsd-pf@freebsd.org
> Subject: Re: Question on packet filter using in and out interfaces
>=20
> Il 20/07/2012 02:44, Greg Hennessy ha scritto:
> > For PF I would tend to filter in the ingress interface, tag flows passe=
d by
> policy and put a generic pass rule on the egress interface permitting the
> tagged flow.
> >
> > The only exception would be assignment of specific flows for shaping.
>=20
> Please see answer on other thread. If PF evaluates rules all together,
> there would be no security difference on using IN or OUT rules.
>=20
> Or does PF not evaluates all rules in configuration file in same phase?
>=20
> Regards,
>=20
> Tonino
>=20
> >
> >
> > Greg
> >
> >
> >> -----Original Message-----
> >> From: owner-freebsd-pf@freebsd.org [mailto:owner-freebsd-
> >> pf@freebsd.org] On Behalf Of Tonix (Antonio Nati)
> >> Sent: Friday, 20 July 2012 1:25 AM
> >> To: freebsd-pf@freebsd.org
> >> Subject: Question on packet filter using in and out interfaces
> >>
> >> I have a basic question is on usage of 'in' or 'out' interfaces, on
> >> practical usage.
> >>
> >> I'm having some talks in PFsense mailing list, and I'm saying there is
> >> no security difference  about using rulesets on output interfaces or o=
n
> >> input interfaces, as PF is evaluating all rules in the same phase.
> >>
> >> At the opposite, I'm told all 'in' rules are evaluated first, than the=
re
> >> is a routing phase, then the 'out'  rules are finally evaluated, so it
> >> is more secure to have only filters on 'in' interfaces.
> >>
> >> Which is the real situation? Does really Packet Filter has any securit=
y
> >> advantage having only 'in' rules, or there is no difference on using o=
ut
> >> interface instead of in interface?
> >>
> >> All start from consideration that using out interfaces would semplify =
a
> >> lot management of complex environments, with interfaces dedicated to
> >> different customers (one OUT rule on specific interface instead of
> >> several IN rules on all other interfaces).
> >>
> >> Thanks for any clear answer you can give.
> >>
> >> Regards,
> >>
> >> Tonino
> >>
> >>
> >> _______________________________________________
> >> freebsd-pf@freebsd.org mailing list
> >> http://lists.freebsd.org/mailman/listinfo/freebsd-pf
> >> To unsubscribe, send any mail to "freebsd-pf-unsubscribe@freebsd.org"
> >
>=20
>=20
> --
> ------------------------------------------------------------
>          Inter@zioni            Interazioni di Antonio Nati
>     http://www.interazioni.it      tonix@interazioni.it
> ------------------------------------------------------------
>=20




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