As more mission-critical business applications become available over IP networks, there is increasing need for equipment-based restoration/protection processes to keep access links at each location continuously available.
One way to do this is by implementing the Border Gateway Protocol (BGP) version 4 at your router, which balances the traffic between your location and two local IP service providers.
BGP chooses the single best path for reaching either destination based on user-defined metrics. Once the path is selected, all the traffic goes out over that path.
An alternative to per-destination load balancing is per-packet load balancing, whereby individual packets are distributed evenly between the two links.
In either scenario, if one of the links goes down, the other link takes all of the traffic.
Implementing BGP4 to achieve ‘dual homing’ resiliency of your enterprise access to the internet, while a prudent endeavor, is not for the do-it-yourselfer. As with all high-reward efforts, proper configuration and maintenance of the Border Gateway Protocol between yourself and multiple ISPs should be done with planning and the assistance of trusted IT professionals with proven experience.
