An essential facet of cloud computing that helps guard against downtime and determines costs is scalability. Scalability enables the expansion or reduction of resources (such as CPU, storage, and bandwidth) according to the demands of an application or service. This adaptability not only mitigates the risks associated with unexpected traffic spikes or loads, which can lead to downtime, but also plays a pivotal role in optimizing costs. With scalable cloud services, organizations only pay for the resources they consume, allowing for efficient budget management and cost savings compared to traditional fixed-capacity IT infrastructures where resources might be underutilized or overstretched during peak times.

Administrative distance is a metric used by routers to determine the trustworthiness of a routing source or path. It ranks routing sources or routes received from different routing protocols according to their reliability and preference. Essentially, administrative distance is a value used by a router to choose the best path when there are multiple routes to the same destination from different routing sources. The lower the administrative distance value, the more trustworthy the route. Different routing protocols have default administrative distances. For example, routes learned from directly connected networks have an administrative distance of 0, which is the most trusted. In contrast, routes learned from less reliable sources, such as external Border Gateway Protocol (eBGP) routes, have higher administrative distances.