How Accurate is the Routing Registry?

By Mirjam Kuehne
Mirjam Kuehne

The Internet Routing Registry (IRR) is a globally distributed routing information database that consists of several databases run by various organisations. Network operators use the IRR to publish their routing policies and routing announcements in a way that allows other network operators to make use of the data. In addition to making Internet topology visible, the IRR is used by network operators to look up peering agreements, determine optimal policies and to configure their routers.

Last month we looked at the completeness of the RIPE Routing Registry (RIPE RR). The encouraging results were presented in an earlier post on CircleID: How Complete is the RIPE Routing Registry?

This month, we wanted to find out how accurate the data in the RIPE RR really is; how well does the data match the information in the BGP routing tables? The more accurate the data in the RR the more useful it is for other operators.

The image below shows the percentage of route objects (for IPv4 address space; shown in blue) and route6 objects (for IPv6 address space; shown in red) in the RIPE RR that match a real route in the BGP routing table. In this context, a "match" means either the exact prefix is registered, or a number of less or more specific prefixes where the total matches the prefix announced in real life are registered.

For IPv4 route objects, the percentage is very high and stable for the last few years — between 85% and 90%. This means that almost all organisations that receive an ASN from the RIPE NCC and that originate a route in BGP have a matching route object registered in the RIPE Routing Registry.

For IPv6, the numbers are a little lower at 80%, but it's growing steadily over time.

The high number of matches between data in BGP and in the RIPE Routing Registry suggests that operators use the RR for operational purposes. It would be interesting to see if not just the prefixes but also the routing policy matches, but that is more complicated and would require a different look at the data.

For more details, please refer to Interesting Graph - How Accurate is the RIPE Routing Registry.

By Mirjam Kuehne

Related topics: IP Addressing, IPv6, Regional Registries