basically i'm designing a business network and i have everything down and ready. then i find out i have to have a back up plan if one of my routers goes down. so what i'm really wondering is, what is the best way to hook up the two routers, would they both send out data to the internet all the time or only when one of them went down?
thanks in advance,
Very complex to really make it redundant. You can't use 2 consumer routers because you can only have a single default gateway. You can get ISP redundancy and even some level of load balancing by using special routers that are designed to have multiple wan connection. Cisco rv042 is one that has been used for a while but there are others. If the router fails though you go down. To get both router and ISP you will have to use commercial routers that have a way to share the gateway and detect a failure of the internet circuit. This would be a SLA function and VRRP to protect the gateway. Something like a cisco 1900 series or larger if you are going to carry a lot of traffic.
Now if you are trying to run a server that is visible from the internet and make it redundant it gets even more complex. In that case you must again use 2 commercial routers and in addition to running VRRP you would run a routing protocol with the ISP..BGP in most cases.