A large enterprise network runs IS-IS. There is a concern that the IS-IS default metrics are not flexible enough. Which IS-IS feature enables increased granularity for traffic on the network?

IS-IS Wide Metrics, defined in RFC 3784, replaces the original narrow TLV-based metrics with extended TLVs that support per-link values up to 16,777,215, allowing administrators to accurately represent bandwidth differences between links and assign meaningful cost distinctions across a large enterprise topology. This granularity is essential for MPLS Traffic Engineering constrained path calculations where narrow metrics collapse many distinct paths into identical cost values. Wide Metrics must be configured consistently across the IS-IS domain and are backward compatible through a transition mode that advertises both metric types simultaneously.

The IS-IS DIS (Designated Intermediate System) is the router elected on a broadcast segment to generate the pseudonode LSP representing the LAN - it is a neighbor election mechanism with no effect on metric range or granularity.

IS-IS Multitopology allows the protocol to maintain separate SPF topologies for different address families such as IPv4 and IPv6, but does not expand or change the numeric range of IS-IS metrics.

IS-IS route leaking redistributes prefixes between Level 1 and Level 2 for inter-area reachability and has no relationship to metric value granularity or range.