By default, IS-IS must be configured on an interface or a level for direct interface addresses to be advertised into that level. To advertise the direct interface addresses without actually running IS-IS on that interface or level, include the passive statement:
For a list of hierarchy levels at which you can include this statement, see the statement summary section for this statement.
Enabling IS-IS on an interface (by including the interface statement at the [edit protocols isis] hierarchy level), disabling it (by including the interface disable statement), and not actually having IS-IS run on an interface (by including the passive statement) are mutually exclusive states.
Note: If neither passive mode nor family ISO are configured on the IS-IS interface, then the router treats the interface as not being operational and no direct IPv4/IPv6 routes are exported into IS-IS.