On Wed, Aug 17, 2005 at 07:39:59AM +0300, Al Boldi wrote: > Soininen Jonne (NET/Espoo) wrote: > > What I would really like to know, if the two networks to which your > > node is connected are subnets of the same network or two distict > > networks with overlapping addresses. Could you please clarify that? > The current kernel implemention treats them as one network with three > subgroupings (subnets). What is needed is to treat them as two > distinct networks because there are two nics. If you wan't them to be distinct, configure them as distinct by making the ip addresses not overlap. But I fail to see any point in treating them as distinct networks because they are both in the same physical network segment. > > >It is a least-effort attempt at constructing a load-balanced > > >fault-tolerant network! > Diagram (f/t proof-of-concept only): > host/gw 10.0.0.1,10.0.1.1 > || > switch---client 10.0.0.2 > | > client 10.0.1.2 > > Problem: > eth1 link fails; host can't return packets to client 10.0.1.2 Since both nics at the host connect to the same switch, it is most likely the same ethernet segment. You do not need two nics if this diagram is correct. One interface can be assigned multiple ip addresses and multiple networks can be routed to it. Have you verified with a network analyzator that the actual problem is with return packets routing? Using multiple nics and multiple networks without any reason on a setup like this causes unnecessary complexity and reduces (not increases) fault tolerance. What is your actual reason for multiple nics and overlapping networks in the same ethernet segment? It is highly unlikely that using one good nic would be the bottleneck. If you wan't more fault tolerance then you need to add a spare gw since some other part of the gw is more likely to blow up than a single nic (typically fans, power supplies or hard drives). If you can afford half an hour per a few years of maintenance breaks and you do not have to process gigabits of traffic per second, go for the simple solution (one nic, one network). Just because it is Linux, you should not try to use solutions that are more complex than absolutely necessary. - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
