From owner-freebsd-net@freebsd.org Wed Jun 13 17:41:27 2018 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 808CD102164F for ; Wed, 13 Jun 2018 17:41:27 +0000 (UTC) (envelope-from kudzu@tenebras.com) Received: from mail-qt0-x242.google.com (mail-qt0-x242.google.com [IPv6:2607:f8b0:400d:c0d::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 152A86FE42 for ; Wed, 13 Jun 2018 17:41:27 +0000 (UTC) (envelope-from kudzu@tenebras.com) Received: by mail-qt0-x242.google.com with SMTP id o9-v6so3188785qtp.3 for ; Wed, 13 Jun 2018 10:41:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tenebras-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=iiQI7UTufGoAq3bUn4wXw/SKP4bwMvcYQkSwKmKBk6k=; b=TWdk3/Jkkzpz4QuquatVidx8h9gqGZg9qP2YotJQ7gbW4qMYSjWgigufy3Rb+fbIh6 iqPNi85uGjm0PkWJuRSUQbtDCJT2hiWuCtJry0ami6WAaM3spdWS8qV5TljQ/QCcaJNv jEBEdQDD7aI3oxJdtKxF7WLEG9YoKrswRSBi8Ovna0m2vfK967uUA0SqUJEHbMGrItKs FObXO6TXzowfptwFu+P0aGrMg1Mjvpv+N7fEltr3FiVZZ4I2GhxHA4WG0nZ15UCgFa/l wmbirN763AlVL23SgdXA/6vEu/6HA812C87xVMiidjRa/5GsEe7zi0wA4rGHb9EOKZWj gARQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=iiQI7UTufGoAq3bUn4wXw/SKP4bwMvcYQkSwKmKBk6k=; b=a6A1HWILkxQpeoomPmQyNctb0XPyySCzSu1ZXDOfPThAiP0+UzKDVGx6m/imITkGG/ rWXM67035Pw9JOp37VPBUSh8+Hv5o73o3a4gHegNQ5xcDcWoMhF+FUCM5+KLbNQDHtqY VAtD3a4JXVW7oJA2uPB8k6y/eXwKZwMvp6IY9TAFz2CcjOW6iR2uu/a9WrX31eoHJ8R2 fpfSJUxNjRSlT179Jq1x/BW/vj2zm6goMDjBVzNka0XLZVRsbToJgp+gma247zvrMKd/ oVTE7pEdpeFvpuobdUsVQuSqyxZ8mtGBTpoxdtlDV39MA+LOHl7jPMGkEAu8FvitQ+Rm 5XJA== X-Gm-Message-State: APt69E2bLivoFrs79+tHdxHqkYAfYkNo3fYfYjKiLv5mkzlbaNaO6plz ICRLi8DjkdXyUeKDAxg8fdJ67YCMwUrjX/iKVtf0nWss X-Google-Smtp-Source: ADUXVKL5dd+x8e/3NsNh266Cdo3hnt+/UdRl9wPljA2SDx2eHqTD85XeJaQGPF3SiQv1KUlTD+AzwymIABWj0WJ3oAs= X-Received: by 2002:ac8:18d7:: with SMTP id o23-v6mr5692801qtk.28.1528911686232; Wed, 13 Jun 2018 10:41:26 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:ac8:297d:0:0:0:0:0 with HTTP; Wed, 13 Jun 2018 10:41:25 -0700 (PDT) In-Reply-To: <918b13e0-aef5-add2-6f5c-530bb5850a3a@wagsky.com> References: <918b13e0-aef5-add2-6f5c-530bb5850a3a@wagsky.com> From: Michael Sierchio Date: Wed, 13 Jun 2018 10:41:25 -0700 Message-ID: Subject: Re: In-kernel NAT [ipfw] dropping large UDP return packets To: "freebsd-net@freebsd.org" , "freebsd-ipfw@freebsd.org" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.26 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Jun 2018 17:41:27 -0000 I see you have a case of Netgraph. Perhaps Julian will chime in. On Wed, Jun 13, 2018 at 10:32 AM, Jeff Kletsky wrote: > On 6/13/18 10:22 AM, Michael Sierchio wrote: > > On Wed, Jun 13, 2018 at 10:16 AM, Jeff Kletsky wrote= : >> >> When a T-Mobile "femto-cell" is trying to establish its IPv4, IPSEC tunn= el >> >>> to the T-Mobile provisioning servers, the reassembled, 4640-byte return >>> packet is silently dropped by the in-kernel NAT, even though it "matche= s" >>> the outbound packet from less than 100 ms prior. >>> >> >> >> Do you have a 'reass' rule before applying nat on inbound traffic? >> >> - M >> > Yes, at the start of the rule set. > > Reassembly confirmed to be working by wireshark examination of the ngtee > "taps" shown > > $ sudo ipfw list > 00001 deny ip from any to any recv ng* > 00004 ngtee 100 ip from any to any proto udp dst-port 500,4500 in > 00004 ngtee 100 ip from any to any proto udp frag in > 00004 ngtee 110 ip from any to any proto udp dst-port 500,4500 out > 00004 ngtee 110 ip from any to any proto udp frag out > 00005 reass ip from any to any > 00006 ngtee 101 ip from any to any proto udp dst-port 500,4500 in // > reassembled in > 00006 ngtee 101 ip from any to any proto udp frag in // never should be > frags after reass > 00006 ngtee 111 ip from any to any proto udp dst-port 500,4500 out // > reass out > 00006 ngtee 111 ip from any to any proto udp frag out // never should be > frage after reass > [...] > > > _______________________________________________ > freebsd-ipfw@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-ipfw > To unsubscribe, send any mail to "freebsd-ipfw-unsubscribe@freebsd.org" > --=20 "Well," Brahma said, "even after ten thousand explanations, a fool is no wiser, but an intelligent person requires only two thousand five hundred." - The Mah=C4=81bh=C4=81rata