RFC 2650 (rfc2650) - Page 2 of 26
Using RPSL in Practice
Alternative Format: Original Text Document
RFC 2650 Using RPSL in Practice August 1999 The IRR is a repository of routing policies. Currently, the IRR repository is a set of five repositories maintained at the following sites: the CA*Net registry in Canada, the ANS, CW and RADB registries in the United States of America, and the RIPE registry in Europe. The five repositories are run independently. However, each site exchanges its data with the others regularly (at least once a day and as often as every ten minutes). CW, CA*Net and ANS are private registries which contain the routing policies of the networks and the customer networks of CW, CA*Net, and ANS respectively. RADB and RIPE are both public registries, and any ISP can publish their policies in these registries. The registries all maintain up-to-date copies of one another's data. At any of the sites, the five registries can be inspected as a set. One should refrain from registering his/her data in more than one of the registries, as this practice leads almost invariably to inconsistencies in the data. The user trying to interpret the data is left in a confusing (at best) situation. CW, ANS and CA*Net customers are generally required to register their policies in their provider's registry. Others may register policies either at the RIPE or RADB registry, as preferred. RPSL is based on RIPE-181 [2, 3], a language used to register routing policies and configurations in the IRR. Operational use of RIPE-181 has shown that it is sometimes difficult (or impossible) to express a routing policy which is used in practice. RPSL has been developed to address these shortcomings and to provide a language which can be further extended as the need arises. RPSL obsoletes RIPE-181. RPSL constructs are expressed in one or more database "objects" which are registered in one of the registries described above. Each database object contains some routing policy information and some necessary administrative data. For example, an address prefix routed in the inter-domain mesh is specified in a route object, and the peering policies of an AS are specified in an aut-num object. The database objects are related to each other by reference. For example, a route object must refer to the aut-num object for the AS in which it is originated. Implicitly, these relationships define sets of objects, which can be used to specify policies effecting all members. For example, we can specify a policy for all routes of an ISP, by referring to the AS number in which the routes are registered to be originated. When objects are registered in the IRR, they become available for others to query using a whois service. Figure 1 illustrates the use of the whois command to obtain the route object for 128.223.0.0/16. The output of the whois command is the ASCII representation of the route object. The syntax and semantics of the route object are Meyer, et al. Informational



