> How can I setup that box that it has only one IP and if connection > through one eth card fails (switch on fire) it activates > second eth card (very probably on some other switch) with same > ifconfig parameters as the first one (ofcourse MAC is different) ? Mario, I don't know how well it works under linux, but assuming your switches are capable, you may wish to investigate the spanning-tree support in the kernel under the 'bridging' configuration option. I don't know all of the effects enabling the bridging software on your box will have, but I do know that automatic [dis/en]abling of redundant links is what spanning tree is all about, and you might be able to come up with something useful using it. Mind you, spanning tree will probably _not_ copy one interface's configuration to another, but it's also not necessary. Just install the IP address in question on a third device -- dummy0, for example -- with a /32 netmask. Once you do that, the ethernet devices (assuming they're up and enabled) will respond to arp requests for that IP address, and will receive traffic for that IP as normal. In any case, once a failover _does_ happen, you will probably want to generate a gratuitous ARP to your gateway to cause traffic to be directed to the new NIC as quickly as possible. This can be important even if you maintain the same MAC address across interfaces, as the switching fabric will need to relearn the path to your address in order to deliver traffic to you. http://www.linux-ha.org has information on the hows and whys of gratuitous ARPing. Thanks, Kyle Sparger - Senior System Administrator ksparger@dialtoneinternet.net - http://www.dialtoneinternet.net Voice - (954) 581-0097 x 122 "Forget college, I'm going pro." - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org
