From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?David_T=E4ht?= Subject: adding nat awareness in routing daemons? Date: Thu, 27 Oct 2011 09:04:31 +0200 Message-ID: <4EA9027F.7000702@gmail.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------000706060206030302010200" To: netdev@vger.kernel.org, bloat-devel@lists.bufferbloat.net Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:37749 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750889Ab1J0HEl (ORCPT ); Thu, 27 Oct 2011 03:04:41 -0400 Received: by faan17 with SMTP id n17so2311355faa.19 for ; Thu, 27 Oct 2011 00:04:39 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------000706060206030302010200 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit after shooting myself in the foot on this several times in the past couple months, I thought I'd ask... Is there a way to determine generically (in linux at least) if outgoing addresses on an interface are being NATTed or not? via netlink? I can come up with a way to do this via parsing iptables's nat table but that's kind of ugly. The scenario I have is two (or more) routers with their external interfaces connected to a shared ethernet/cable segment. Both do NAT on their external interfaces for ipv4 (but don't do nat, at least currently, for ipv6). Their private networks are usually connected together via various means (mesh mostly), which can fail, and it would be nice to be able to add the external connectivity as a fallback without having to worry about NAT. e.g. something like if (nat_status(&this_interface)) { if(this_interface & IPV4_NO_NAT) send_route4_calculations(); if(this_interface & IPV6_NO_NAT) send_route6_calculations(); } Where I did myself in on this was in the lab http://io.lab.bufferbloat.net:8080/ -- Dave Täht --------------000706060206030302010200 Content-Type: text/x-vcard; charset=utf-8; name="dave_taht.vcf" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="dave_taht.vcf" begin:vcard fn;quoted-printable:Dave T=C3=A4ht n;quoted-printable:T=C3=A4ht;Dave email;internet:dave.taht@gmail.com tel;home:1-239-829-5608 tel;cell:0638645374 x-mozilla-html:FALSE version:2.1 end:vcard --------------000706060206030302010200--