Summary

  • RPSL import and export expressions describe a policy a database object declares; they do not observe route exchange.
  • A current BGP claim needs time-aligned routing evidence, while a policy claim needs the retrieved object and its provenance.

RIPE describes the aut-num object as a primary RPSL object for autonomous-system routing policy. RFC 2622 supplies the language for policy expressions, including import and export. That makes an aut-num object useful for a narrow question: what policy has been registered in that object?

It cannot answer a different question merely because the words look operational. An import expression does not prove that a peer accepted a route. An export expression does not prove that a prefix is announced, propagated, reachable, transited or preferred. A record may lag a configuration change, express an intended relationship that was never activated, or omit exceptions made in practice.

The disciplined record keeps both layers. Preserve the object, exact expression, source URL and retrieval time as registration-policy evidence. Then obtain separately scoped, time-aligned BGP observations for any claim about live announcements or visibility. Neither layer substitutes for the other.

Sources