One of the first things this chapter suggested was to consider extra inventory. What we haven't really covered yet involves online backups. Most server-class motherboards include not just one, but two on-board network modules. Each module commonly provides four Ethernet interfaces.
Usually each interface is considered separate, and two interfaces from each module are connected to two switches in the data center. This allows server administrators to seamlessly perform maintenance on either switch without disrupting our network traffic. Furthermore, if a switch or network module fails, there's always a backup available.
In our working example, we would need eight 1 Gb/s interfaces to avoid experiencing network congestion. ...
