Routeorigin

Routeorigin is a term used in the context of Border Gateway Protocol (BGP) to refer to the origin of a route as indicated by the BGP ORIGIN attribute. This attribute is one of the well-known path attributes that accompany BGP route advertisements and helps distinguish where a route originated before being propagated through the network.

The ORIGIN attribute encodes three possible values: IGP, EGP, and INCOMPLETE. IGP indicates that the route originated from an interior gateway protocol within the local autonomous system (AS). EGP reflects an origin from an exterior gateway protocol, a historical designation that is largely of archival relevance. INCOMPLETE is used when the route’s origin is unknown or when the route has been redistributed from another routing protocol or manual configuration. In practice, EGP is rarely used today, while INCOMPLETE is common for routes redistributed from static routes or other protocols.

In BGP route selection, the ORIGIN attribute is one of several factors shaping the best-path decision. The typical preference order is IGP origin (most preferred) > EGP > INCOMPLETE (least preferred). This ordering helps networks favor routes believed to originate from more tightly controlled internal processes, though exact behavior can vary with vendor implementations and policy.

Routeorigin is distinct from, but related to, Route Origin Validation (ROV) in the context of RPKI. ROV checks whether a prefix originated by the stated ASN, based on Route Origin Authorizations (ROAs). While ORIGIN is a local BGP attribute affecting route selection, ROV provides a global security check to mitigate origin-based routing hijacks.

Overall, routeorigin describes the origin status of a BGP route and informs routing decisions, policy, and, in modern deployments, integration with origin-validation mechanisms.