The Internet Routing Registry (IRR) is a globally distributed routing information database. The IRR consists of several databases run by various organisations in which network operators can publish their routing policies and their 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, more recently, to configure their routers.

It is often claimed that the IRR is not used enough, is not complete, is not up to date and is, therefore, not a reliable source for routing information. And because the IRR is spread over multiple databases, some parts of it might be more complete and up to date than others.

The RIPE NCC is also maintaining a Routing Registry (RR) as part of the RIPE Database. It is considered good practice to register routing policy in a routing registry. Having routing policy registered in the RR, makes it easier for network operators to configure and manage their routers. Some Internet service providers even require their customer’s routes to be registered in the RR before agreeing to route these address prefixes. We were interested to find out how many of those organisations that received an Autonomous System Number (ASN) from the RIPE NCC use the RIPE RR. We did this in three steps:

  1. Count all ASNs assigned by the RIPE NCC
  2. Find out how many of those ASNs are visible in the routing system
  3. And of those, see how many are listed as origin AS in a route or route6 object in the RIPE RR

The image below shows how many of those ASNs that were assigned by the RIPE NCC and that are visible in the routing system are also listed as origin AS in a route or route6 object in the RIPE Routing Registry.

For IPv4 route objects, the percentage is very high and stable for the last few years—around 95%. This means that almost all organisations that receive an ASN from the RIPE NCC and that originate a route in BGP also register a route object in the RIPE Routing Registry. Even without knowing how accurate and up-to-date these objects are, the fact that such a large fraction is registered is a great sign.

For IPv6, the numbers are a little lower—86% of RIPE NCC assigned ASNs that originate IPv6 routes in the routing system are also registered in the RIPE Routing Registry. In 2007, this number was only 60%, so it has been steadily increasing over time.

In a future study, we will investigate further the accuracy of these route objects.

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

Written by Mirjam Kuehne