If you configure a metric of 200 on an IS-IS-enabled interface and see a metric of 67 on another device's routing table, what could explain this behavior?

When configuring IS-IS, it is important to understand the concept of metrics and how they can be set and interpreted in different ways based on the IS-IS configuration. The correct answer involves the possibility that Router-1 is sending both standard (original) and wide metrics.

In IS-IS, there are two types of metrics: standard metrics, which are expressed in the range of 1 to 63, and wide metrics (or extended metrics), which are used for higher bandwidth links and can range from 0 to 16777215 when the wide metric format is in use. If Router-1 is configured to send both standard and wide metrics, it may be using the wide metric format for some links while defaulting to the standard metric for others.

The sighting of a metric of 67 in another router’s routing table suggests that this router could be interpreting the wide metric from Router-1 but still supporting the standard metrics, leading to potential discrepancies in the metrics as they are linked in the routing decisions.

This scenario is significant because it addresses the interoperability of different metric configurations and how they can coexist within an IS-IS network. This insight allows for understanding how routing decisions may vary based on the type of metrics in use.