Thanks for the suggestion, I'll read up more about them. The bond0 and just works sounds simple which is a Good Thing! The problem was the last time I tried to cross connect multiple switches, everything just died so there must be something a bit more involved? :D In the mean time since my post, I came across STP (spanning tree protocol) that seems to be designed to handle this sort of thing, i.e. figure out the shortest path and prevent network shortcircuit like what I had experienced with cross connecting multiple switches. But it apparently takes 50 seconds to reconfigure anytime sometime in the circuit fails. There is supposedly a Rapid STP that only takes 3 seconds. Several couple-of-years old search results indicate that it was tested in 2.4 kernel and will be in 2.6 kernel. However, I cannot seem to find anything newer that confirms if such functionality is really in the current kernel. Anybody has any idea? On 7/11/10, Jerry Franz <jfranz at freerun.com> wrote: > On 7/10/2010 2:21 PM, Emmanuel Noobadmin wrote: >> I've been reading that it's possible to set up a system with multiple >> NIC to provide redundant internet connectivity such that it will >> switch to a secondary connection if the primary ISP fails. >> >> Is it possible in a similar way to setup redundant LAN routing? I read >> that it is possible to aggregate/bond multiple NIC to stackable >> switches that support link aggregation and redundancy. But if only >> simple switches are available, is something like this possible? >> >> e.g. >> System A >> eth0 -> lan switch/router 1 >> eth1 -> lan switch/router 2 >> >> System B >> eth0 -> lan switch 1 >> eth1 -> lan switch 2 >> >> Then somehow specify that, if lan switch 1 fails, the two systems will >> switch to using switch 2 so that in case of a switch failure, the >> network continues to remain operational. > > Yes. You can do it. I've done it before. All you need is the right > choice of bonding mode . You set up bond0 for eth0 and eth1 and it 'just > works'. To make it more robust, cross-connect the two switches as well. > > -- > Benjamin Franz > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >