From owner-freebsd-hackers Tue Oct 19 21:41:43 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from jason.argos.org (a13b146.neo.rr.com [204.210.197.146]) by hub.freebsd.org (Postfix) with ESMTP id 1B8711AAAA for ; Tue, 19 Oct 1999 21:41:34 -0700 (PDT) (envelope-from mike@argos.org) Received: from localhost (mike@localhost) by jason.argos.org (8.9.1/8.9.1) with ESMTP id AAA29576; Wed, 20 Oct 1999 00:41:32 -0400 Date: Wed, 20 Oct 1999 00:41:32 -0400 (EDT) From: Mike Nowlin To: Sam Samalin Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Class C hack instead of ifconfig aliases In-Reply-To: <380CCA4D.8A7230BB@ionet.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Is there anyway to bind a class C to an interface without a lot of > aliases? whats the downside of aliases? I have a 2.2.8 hack that does > the C, but I'd like to avoid having to port it to 3.3. What do you mean by "bind a class C"? Make an interface so it will respond to incoming requests for 10.1.2.x? ewww, yuck! Aliases are (for me, at least) a love/hate relationship. I have a few machines floating around on some of my networks that use them to get around some routing problems, and they generally work quite well for incoming connections... I imagine that FBSD probably has the same problem as Digital UNIX for outgoing connections, though.... Picture, if you will, the following: ed0 192.168.2.4 netmask 255.255.255.0 alias 208.132.36.131 route 192.168.2.0/24 -> ed0 route 0.0.0.0/0 -> gateway 208.132.36.129 Any packets sent to the gateway get 192.168.2.4 as the source, not 208.132.36.131 -- the gateway will send the packet off to the rest of the world, where it gets immediately dropped due to the "internal use only" source IP address. IMHO, it should notice that it's going to a member of the aliased network, and change the source IP to the alias address, not the "normal" 192.168.2.4 address. This can (usually) be fixed at the gateway with some fancy natd/ipfw lines, but it gets ugly... If FreeBSD does NOT have this "problem", I think we should send a copy of it off to DEC -- I'll dig up my sequence number from the problem call I placed a couple years ago regarding this.... :) I finally fixed it on the Alpha by purchasing another (really expensive - damn TurboChannel bus) network card to handle the 2nd IP address...... mike To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message