The Advisory Attribute David Kessens ____________________________________________________ The Advisory Attribute David Kessens RIPE NCC Document: ripe-131 Obsoletes: ripe-130 Updates: ripe-181 Scope This document describes the advisory attribute of the route object. Description Some autonomous systems may benefit from specific private information stored in the routing registry on a per route basis. The advisory attribute of the route and aut-num objects enables this. It simply provides a mechanism by which the maintainer of a route or autonomous system object can register an arbitrary text string intended for the operator of a specific 'target' AS. The syntax and semantics of the text string are defined by the operator of the 'target' AS concerned and are beyond the scope of this document. The advisory attribute of a route object applies to the specific route. The advisory attribute of an aut-num object is intended to apply as default to all routes originated by the autonomous system in question, providing a shorthand notation if the same advisory applies to most or all such routes. If both are present the advisory attribute of a route object takes precedence over the advisory attribute of the aut-num object. As with all advisories the specific semantics are defined by the 'target' AS. It is recommended to limit the use of advisories as much as possible and to use the standard routing registry instead. It should be considered that the use of this attribute requires additional effort by the maintainers of the objects concerned. It is important to establish their motivation to register and maintain this information properly. ____________________________________________________ ripe-130.txt Page 1 The Advisory Attribute David Kessens ____________________________________________________ Definition advisory: Advises a specific 'target' AS to use the information that is defined in this attribute. Format: The AS specific information is intended for use by ASnnnn, the 'target' AS, only. The syntax of the AS specific information is defined by ASnnnn and beyond the scope of this document. It can be obtained by contacting the administrative contacts of ASnnnn which can be found in the corre- sponding aut-num object. Status: optional, multiple lines allowed Acknowledgements This document is based on a draft by Dale Johnson of MERIT. Adding advisories to aut-num objects was suggested by Christian Panigl of ACOnet. ____________________________________________________ ripe-130.txt Page 2