From owner-freebsd-net@freebsd.org Tue Sep 22 08:07:09 2020 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 3AD093E1136 for ; Tue, 22 Sep 2020 08:07:09 +0000 (UTC) (envelope-from list1@gjunka.com) Received: from msa2.yoonka.com (yoonka.com [88.98.225.149]) (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 (2048 bits) client-digest SHA256) (Client CN "msa2.yoonka.com", Issuer "msa2.yoonka.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BwYn7521Hz4fQY for ; Tue, 22 Sep 2020 08:07:07 +0000 (UTC) (envelope-from list1@gjunka.com) Received: from venus.yoonka.com (venus.yoonka.com [10.70.7.24]) by msa2.yoonka.com (8.15.2/8.15.2) with ESMTPS id 08M870Ml046509 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO) for ; Tue, 22 Sep 2020 08:07:00 GMT (envelope-from list1@gjunka.com) Subject: Re: sshd on two fibs To: freebsd-net@freebsd.org References: <48e3aa5d-3123-45f2-5c46-6851ad90110a@gjunka.com> <4d78a442-147f-db32-72ae-487d3e0197cc@grosbein.net> <9ff48087-b24e-263c-b1c2-030318722ec1@gjunka.com> From: Grzegorz Junka Message-ID: <08ecc039-99eb-721c-40f5-28b75be392d3@gjunka.com> Date: Tue, 22 Sep 2020 08:07:00 +0000 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Rspamd-Queue-Id: 4BwYn7521Hz4fQY X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of list1@gjunka.com designates 88.98.225.149 as permitted sender) smtp.mailfrom=list1@gjunka.com X-Spamd-Result: default: False [-1.92 / 15.00]; RCVD_TLS_ALL(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:88.98.225.149]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-net@freebsd.org]; TO_DN_NONE(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_HAM_LONG(-1.00)[-1.004]; DMARC_NA(0.00)[gjunka.com]; NEURAL_SPAM_SHORT(0.34)[0.336]; NEURAL_HAM_MEDIUM(-0.95)[-0.951]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:56478, ipnet:88.98.192.0/18, country:GB]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[freebsd-net] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Sep 2020 08:07:09 -0000 On 21/09/2020 07:35, Eugene Grosbein wrote: > 21.09.2020 14:21, Grzegorz Junka wrote: > >>> All you need is telling kernel to use right gateway based on source IP address despite of default route, >>> this is called policy-based routing and you can achieve that with single ipfw rule: >>> >>> ipfw add 2000 fwd $gateway2 ip from $wan2ip to any out xmit $wan1 >>> >>> That is: redirect IP packets with source of second WAN interface ($wan2ip) to right gateway of that WAN ($gateway2) >>> if they are going using (wrong) route to WAN1. That's all. >> Thanks Eugene. I am reluctant to add firewall rules because the second interface is configured as being in fib 1. > Existance of the fib 1 does not matter for your case, at all. > >> This is so that jails, which are also started with fib 1, can use the proper routing table. > Exactly. > >> I don't want to add complexity where it isn't necessary, unless there is no other option. > Me too. And single ipfw rule is minimal possible addition, all other solutions are more complex. > >> Is it possible to somehow configure sshd to use the proper routing table? > It is possible but it won't help you because every routing table contains routes that do NOT depend > on source IP address of the packet and you need such policy-based routing. Standard routing tables > do not offer policy-based routing, so they are useless for you. > > You could read rc.conf(5) manual page to learn about _fib knob (f.e. sshd_fib="1") > but it won't solve your problem. You could also add your own startup script to run second copy of sshd > with its own PID file and listening IP address and FIB but that would be much more complex solution. > > Just tell kernel you need policy-based routing with ipfw. This just works. > No need to utilize second FIB just because you already have it. > OK, yeah, sounds reasonable. Thanks for explaining! GrzegorzJ