Cisco Systems Juniper Networks Cisco Systems Thomson Reuters IGP protocols traditionally compute best paths over the network based on the IGP metric assigned to the links. Many network deployments use RSVP-TE based or Segment Routing based Traffic Engineering to enforce traffic over a path that is computed using different metrics or constraints than the shortest IGP path. Various mechanisms are used to steer the traffic towards such traffic engineered paths. This document proposes a solution that allows IGPs themselves to compute constraint based paths over the network without the use of the above mentioned traffic engineering technologies.