What is the maximum metric for a router using standard metrics with a single link to a Level 2 IS-IS neighbor?

The maximum metric for a router using standard metrics in the context of IS-IS (Intermediate System to Intermediate System) protocol is indeed 63. IS-IS uses a metric scale to signify the cost of routing information, and within standard metrics, this maximum value is established to ensure that network resources are utilized efficiently and avoid potential routing loops or misconfigurations.

Higher metrics can be utilized in various networking contexts, but the standard metric maximum is capped to help maintain a reliable and manageable network topology. Understanding this limitation is crucial for network design and routing performance optimization.

While other options suggest higher maximums, they pertain to extended metrics or non-standard configurations outside of the default metric settings commonly employed in Level 2 IS-IS routing scenarios. Thus, in standard operations, a metric of 63 is sufficient to represent the routing cost effectively.