From owner-freebsd-questions Tue Apr 20 0:18:44 1999 Delivered-To: freebsd-questions@freebsd.org Received: from pericles.IPAustralia.gov.au (pericles.IPAustralia.gov.au [202.14.186.30]) by hub.freebsd.org (Postfix) with ESMTP id 2B5DF1530E for ; Tue, 20 Apr 1999 00:18:38 -0700 (PDT) (envelope-from Stanley.Hopcroft@ipaustralia.gov.au) Received: (from smap@localhost) by pericles.IPAustralia.gov.au (8.9.1/8.9.1) id RAA29380; Tue, 20 Apr 1999 17:15:39 +1000 (EST) X-Authentication-Warning: pericles.IPAustralia.gov.au: smap set sender to using -f Received: from noteshub01.aipo.gov.au(10.0.100.21) by pericles.IPAustralia.gov.au via smap (V2.0) id xmac29350; Tue, 20 Apr 99 17:15:26 +1000 Received: by noteshub01.aipo.gov.au(Lotus SMTP MTA v4.6.3 (778.2 1-4-1999)) id 4A256759.002778AE ; Tue, 20 Apr 1999 17:11:07 +1000 X-Lotus-FromDomain: IP_AUSTRALIA From: Stanley.Hopcroft@ipaustralia.gov.au To: freebsd-questions@freebsd.org Cc: Carl.Makin@ipaustralia.gov.au Message-ID: <4A256759.00277723.00@noteshub01.aipo.gov.au> Date: Tue, 20 Apr 1999 17:10:07 +1000 Subject: IPFW and bridging Mime-Version: 1.0 Content-type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Dear Ladies and Gentlemen, I am writing to ask your help with the new BRIDGE kernel option, to use ipfw to discard packets that will cause *chaos* if they are forwarded (eg DHCP clients on 2 LANs each with their own DHCP server connected by a transparent bridge ... clients are offered addresses by both servers, which may not be what you want ...) Please would you tell me 1 is it possible to bridge based on LLC SAP (eg 0xAA for 802.3 encapsulated IP packets, 0x04 for SNA etc) ? 2 is it possible to bridge based on any other part of the packets contents. man ipfw refers to /etc/protocols but my 2,2.8-STABLE router has no such file ? 3 How can I do these things ? My kernel, 2.2.8-STABLE, has option BRIDGE set, the sysctl options for bridge are visible, the box has two ed interfaces. The box certainly bridges - as the DHCP catastophe informed me - but I need to restrain it. Thank you, Yours sincerely. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message