From nobody Wed Apr 24 18:00:57 2024 X-Original-To: freebsd-net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4VPmxn0qs5z5J44r for ; Wed, 24 Apr 2024 18:01:01 +0000 (UTC) (envelope-from gshapiro@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4VPmxn0BmDz3xc5; Wed, 24 Apr 2024 18:01:01 +0000 (UTC) (envelope-from gshapiro@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1713981661; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=84doZlQx2jEr8yE/PN8UPr98OvXMS8in7LgoEKCx2es=; b=Pju9zGF3B/KqFHePpOPAIQIRT7i+dl8pMFywBicNuIGxIIR9W/tDqlHWprwBoJ13854fhI x7vs55Ny+FZ1RbFzhXwAFR8rm6H7jDthR0XFYBM7X7hcGjAN9vLaPDWoWxAPUbx8Tl7i8K e2zItClanWSmi5fA40+2lDuyST4NiJbP1B9oEq9u+bDo7qc8g2pP5PhNqUXnK5dtTnseUb 5ZslRXcldni3iquSNGgnAyFNOfwHoKoXY2CN0qg4VjyO8tB4HesLflA/TvxG3mNxSiPnQM 88b8grsvGSrE1knJgHzDjnbTPzs+8HJjJbiWGVzm5fnMmLo9NmzrW7vSYM0duw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1713981661; a=rsa-sha256; cv=none; b=i78Lm5YM2uCf3m6r+WfJZN2mEftDNKRQ5u3C1BljDQQARkoKI+5ie//uP29d2GRZKx0j3r 4er5pdynMSYXSJ3tvw4G1hLCN9cpSIDS955J/Ii5OQg+K+LwXFl91UlSfEsXcTsttVA83F /IrLfKfVp1MBViIiIiWEoqrIm5O4qDJGnS0MyTk83gjl8xLVVyAfThvon2hzb6ZE3d4B7X 2wMEGIbCUGn30enDmuiK0PPSID2n32I5jughD9cZWa3MpXf/nSFJBreKhRJbBY7gkNNcx3 K2LPYGF1LUZrWHxsWd9W/RRYA8ILNpu4B8AJisiVO4jCJDaDJtxA9LgZU02flA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1713981661; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=84doZlQx2jEr8yE/PN8UPr98OvXMS8in7LgoEKCx2es=; b=i6hmk+EwgRMjgHb84EaVHUE4QxeHHTjPajNEac7y9ldowFPGce1uGsmU5U5kZ37X2Oka+9 k5gJuScnRjoDaCkvj9oQQdR1E560zB03vsgdTiEVwa9yojQOFExUgs55rkJK68Zci7syO9 QoTQcqqzxwub09kJycydfhGL1CiE4n61LrLnwU/UTGgac2saU2zkklQGWxi3KtuMxchBUS 5w7TUiVnlbnrpAquu3L2VjF1VfAS0nWYD9CparsifbL8IVvoEnImKIgb5SYwiFD3Cioj7n w9ogV6q2eJRiAhiLP3l7KoQLz+p1Zrc2fX/sdS29xq3bC8QaPxHQMcCkcuSofw== Received: from thornystick.local (thornystick.gshapiro.net [IPv6:2a0a:280:2357:5506::2ee5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: gshapiro) by smtp.freebsd.org (Postfix) with ESMTPSA id 4VPmxl3CNNz1QMZ; Wed, 24 Apr 2024 18:00:59 +0000 (UTC) (envelope-from gshapiro@freebsd.org) Date: Wed, 24 Apr 2024 11:00:57 -0700 From: Gregory Shapiro To: "Rodney W. Grimes" Cc: freebsd-net@freebsd.org Subject: Re: Source IPv4 address selection vs BGP IX connection Message-ID: <3exr7zmcxnfxuofbyf57gdbzxxrgntprydeesbjsparq3xgeri@p4irynwruq7f> References: <202404241742.43OHghWB055177@gndrsh.dnsmgr.net> List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202404241742.43OHghWB055177@gndrsh.dnsmgr.net> > The mistake your making, IMHO, is that an IX connected eBGP FreeBSD > router _SHOULD NOT_ be doing ANYTHING other than BGP on the IX > connected interface, and anything like DNS and outbound SMTP should be > going inward on the AS, not outward to the internet. Fair point and thank you for the advice. I am locking it down to an extent (denying all inbound ports except 22, 179 from an ipfw table list of trusted hosts/peers/upstreams/downstreams) but not as tightly as you suggest as I do use some on-Internet services. Specifically, port 25 to my own mail server (not unwashed Internet service, but sitting off of a different network) for system generated mail (cron, /etc/periodic/ script output), 53 to admittedly "unwashed" Google DNS, and 123 to FreeBSD's NTP pool (again "unwashed" to an extent). I will look at using local instances for the latter two. I still see value in source IP selection, even outside of the IX use case.