Date: Wed, 16 Nov 2016 12:05:22 +0100 From: Oliver Peter <lists@peter.de.com> To: Big Lebowski <spankthespam@gmail.com> Cc: Oliver Peter <lists@peter.de.com>, freebsd-pf@freebsd.org, freebsd-net@freebsd.org Subject: Re: NAT Reflection rules for FreeBSD PF Message-ID: <20161116110522.GD1675@mail.opdns.de> In-Reply-To: <CAHcXP%2BcQD=7nF2s65RnX-fkG_Rz7zQJYrO=9Z_zLwLOucio0NQ@mail.gmail.com> References: <CAHcXP%2BeMrDO0V276DuYKwHMoK8BrAYMhH6b16%2BVhtXRDrKAuAQ@mail.gmail.com> <20161115113705.GB1675@mail.opdns.de> <CAHcXP%2Bcfn7%2B_6pH=cSJ2mEnNPaH1N3Dv7na%2BJiu0=PR-wBZR0A@mail.gmail.com> <20161115132609.GC1675@mail.opdns.de> <CAHcXP%2BcQD=7nF2s65RnX-fkG_Rz7zQJYrO=9Z_zLwLOucio0NQ@mail.gmail.com>
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--zS7rBR6csb6tI2e1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Nov 15, 2016 at 02:49:18PM +0000, Big Lebowski wrote: > On Tue, Nov 15, 2016 at 1:26 PM, Oliver Peter <lists@peter.de.com> wrote: >=20 > > On Tue, Nov 15, 2016 at 01:03:54PM +0000, Big Lebowski wrote: > > > On Tue, Nov 15, 2016 at 11:37 AM, Oliver Peter <lists@peter.de.com> > > wrote: > > > > > > > El duderino, > > > > > > > > On Mon, Nov 14, 2016 at 10:30:59PM +0000, Big Lebowski wrote: > > > > > > > > > > I am trying to set up a 11.0-R PF based NAT for group of jails th= at > > needs > > > > > to be able to talk to services on other jails, just as if they'd = be > > > > clients > > > > > from outside of the network. Apparently, this is called 'NAT > > reflection' > > > > > and I was able to find examples for OpenBSD PF here: > > > > > https://www.openbsd.org/faq/pf/rdr.html (bottom of the page). > > > > > > > > > > Obviously, their syntax doesn't work on FreeBSD PF, so how to > > achieve the > > > > > same thing? How to allow jails NAT'd on $ext_if (xn0) coming from > > > > > $jails_net (192.168.0.0/24 aliased on lo0) to talk to each other, > > via > > > > the > > > > > $ext_if external IP? > > > > > > > > We did something similar in a customer setup a while ago: > > > > > > > > nat on $int_if from $jail_host to any -> $int_ip > > > > rdr pass on $int_if proto { tcp, udp } from $jail_host to > > $ext_if > > > > port{ $service1, service2 } -> $int_lb > > > > > > > > Cheers > > > > > > Thanks for your response Olivier! Would you mind elaborating on it a = bit > > > more? I don't understand what you're trying to achieve here, since the > > NAT > > > doesn't happen on $int_if (lo0) but instead on $ext_if (xn0). The $in= t_if > > > only holds the jail's IP addresses from the $jail_net range. How does > > that > > > compare? > > > > Ah, it could be that this is a bit different since you only have a sing= le > > machine, our example was a gateway with two interfaces (ext/int) doing = NAT > > for some machines behind. Since your packets are created on lo0 and > > routed to xn0 it might be different. > > Another idea would be to re-route the packets between the two interface= s: > > pass out quick on $ext_if route-to $int_if from ($int_if:networ= k) > > to $ext_if:network > > > > This might interfere with your regular outgoing traffic; maybe the "to" > > part needs a bit tuning. Furthermore I'm not sure about the source > > addresses... We have this in production to route some DNS traffic via > > VPN. > > > > Split horizon DNS is no option? > > Sorry for not being very helpful. >=20 >=20 > No worries, you've been most helpful so far :) >=20 > The host has two interfaces, I simply chose lo0 for jails, because I wasn= 't > aware it would matter, so, if needs be, I can migrate jails IP's from lo0 > to xn1 - would it make difference in that I'd now be able to implement the > reflection somehow, or would I need to get the jails out of the host > entirely and make the host to provide gatefway functionality only? Well, you made me curious about this so I created two jails on a 11-RELEASE test machine with a single external address. jail0 is on lo0 jail1 is on lo1 For outgoing service I have: nat on em0 from lo0:network to any -> ($ext_if) nat on em0 from lo1:network to any -> ($ext_if) The interesting thing here is that /all/ traffic happens on lo0 - even for jail1 which sits on lo1 only - which I don't understand. Furthermore it seems that since the target machine is also the source machine and does not need any routing the packets are not translated but directly routed, I tested this with: rdr pass on lo0 proto tcp from lo1:network to $ext_ip port 2224 -> $jail0 = port 22 jail0 only sees the internal IP since we do not route here. I was thinking about a mixture of PF and IPFW but this is getting nasty now. --=20 Oliver PETER oliver@gfuzz.de 0x456D688F --zS7rBR6csb6tI2e1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlgsPXEACgkQ6LH/IUVtaI/LIACdHdPwKXl0GLm91Kp7pRXEw+Mn ofUAn1ow+dsoP6cEuf565fcdSSGAQ2HM =8pJP -----END PGP SIGNATURE----- --zS7rBR6csb6tI2e1--
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