Date: Fri, 1 Oct 2004 16:57:57 -0700 From: "Richard Marriner" <richard@syix.com> To: "'Kevin Glick'" <keving@sbfnet.com> Cc: freebsd-questions@freebsd.org Subject: RE: Quickie... Hopefully! Message-ID: <20041002000247.A35E55C40@richard.syix.com> In-Reply-To: <20041001225425.1508E34F08D@lynx.syix.com>
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Kevin, This is exactly what is happening.. I have found though that if I give the interface two Ips with ifconfig and set the default route to our newest router (Cisco 7204) somehow I am able to do what I am wanting. (I guess the Cisco is lots smarter than our Tiara..) I am aware that having two numbered networks on one physical lan is not good practice, but this is only a temporary solution and VLANs are planned for the near future.. As for our daemons, most are running promiscuous to any IP, but I am aware I will need to "double check" the configs.. Thank you very much for your reply.. Richard > -----Original Message----- > From: Kevin Glick [mailto:keving@sbfnet.com] > Sent: Friday, October 01, 2004 3:54 PM > To: 'Richard Marriner' > Cc: freebsd-questions@freebsd.org > Subject: RE: Quickie... Hopefully! > > Richard, > > I've done the same thing a few times. To get the full > description, check > the ifconfig man page and look for "alias". There's two > problems with doing > this: first, BSD can't have two default routes. Windows > allows you to set > two default gateways, and it works because of the "Route > Discovery" built > into it (this is why a windows machine can use a gateway > that's not on it's > local subnet...but, that's another topic). Second, if you've > got servers > set to listen only on a specific IP (apache, etc) it still > won't work, even > with the alias. > > Example: > 1.1.1.1-1.1.1.255 -->from ISP #1 \ > /-> 1.1.1.2 > -->hub/switch --> > FreeBSD fxp0 > 2.2.2.1-2.2.2.255 -->from ISP #2 / > \-> 2.2.2.2 > > In the crude diagram above, both ISPs feeds end up coming > into a hub/switch > that your BSD machine is plugged into. The normal ifconfig > on the device is > 1.1.1.2 netmask 255.255.255.0. You would then: "ifconfig > fxp0 inet 2.2.2.2 > netmask 255.255.255.0 alias" the device. This will work, as > long as routing > is setup correctly. Any request for 2.2.2.2 from anywhere in > the world > would end up at the same machine/interface as a request for > 1.1.1.2. The > problem lies in getting data out with the aliased address. > The default > route on the machine would be 1.1.1.1 and all traffic goes > there. If you > have specific traffic that you want to go out with the > 2.2.2.2 address, > you'd have to add routes for each DESTINATION IP: "route add > -net 3.3.3.3 > -netmask 255.255.255.0 2.2.2.1" and so on. BSD isn't smart > enough to do > source based routing. So the traffic will come into 2.2.2.2 > via ISP #2, but > the replies/ACKs will go out via ISP #1. Any traffic > generated from the > machine, without a specified SOURCE IP will go out as > 1.1.1.2, and get sent > via the 1.1.1.1 gateway. > > The other problem with the diagram above is that you've got > two subnets > running on the same lan, which breaks most rules of > networking. This can be > remedied with a few vlans, but again, that's another topic. > > Hope this helps. I'm sure most of this info is correct, but > I'm more than > willing to have somebody set me straight. > > Kevin Glick > ITS Manager > keving@sbfnet.com > Sterling Business Forms > > > -----Original Message----- > From: owner-freebsd-questions@freebsd.org > [mailto:owner-freebsd-questions@freebsd.org] On Behalf Of > Richard Marriner > Sent: Friday, October 01, 2004 3:25 PM > To: freebsd-questions@freebsd.org > Subject: Quickie... Hopefully! > > Dear list, > > Just wondering if there is anyway (preferably simple.) to > have two ip > addresses on the same NIC that are different networks. > > A little background. We are in the process of changing ISPs, > we now have > two circuits going to two differnet ISPs. Because of this > change we have to > renumber our entire network. Being an ISP ourselves we have > a handful of > servers that run FreeBSD. While trying to get one of our > test servers to > talk to both networks from the internet we fail, I think > because even though > your request is on the new numbers FreeBSD still trys routing > the response > back through our old gateway. Another question, I know in > Windows XP you > can set two gateways, two ips, etc. Can you do this in FBSD? > Our windows > boxes are talking fine on both networks. > > Any help or suggestions appreciated... > > Richard Dean Marriner II > SYIX.COM --=-- Network Administrator > 530-755-1751x206 - richard at syix.com > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org" > >
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