A New Source For Authoritative Routing Data: ARIN WHOIS

Job Snijders
4 min readDec 19, 2017


I'd like to share an update on some routing security activities that
ARIN, NTT Communications, YYCIX (Calgary Internet Exchange), the NLNOG Foundation, and the arouteserver project have been collaborating on. Quite some puzzles pieces were brought together! :)

Traditionally, there are two commonly-used methods to signal to your
peers or upstream providers what Origin ASN(s) are allowed to originate a given IP prefix. As an operator, you can either create a "route object" in the IRR, or you can compose a Letter Of Agency (LOA) and send that to your upstream provider for manual verification.

When it comes to manual verification of routing data (such a LOA), one of the big questions is "what data source is actually authoritative for the verification?". In the ARIN registry the so-called "OriginAS" attribute can be used for this purpose. The OriginAS attribute can only be set or modified by authorized accounts (such as the holder of the IP space). This makes the OriginAS attribute a very reliable source of truth! ARIN shared some notes on LOAs & OriginAS in the following article: https://teamarin.net/2016/07/07/origin-as-an-easier-way-to-validate-letters-of-authority/

That teamarin posting got me thinking: clearly there is a lot of valuable routing information in the ARIN WHOIS registry. What if we make the process such that you don't have to email in a LOA, and, have the recipient verify it against against the web interface output (which you updated before sending in the LOA). What if the prefix-filter generation software could just pro grammatically fetch all (CIDR, OriginAS) tuples from the ARIN WHOIS registry and load that into the list of prefixes a customer is allowed to announce. Just like we do with IRR objects!

A few weeks ago I approached John Curran from ARIN asking whether we could work out a mechanism to somehow obtain a computer parsable rendering of the CIDR/OriginAS data in the ARIN WHOIS registry. The path forward turned out to be an agreement between the NLNOG Foundation and ARIN, which authorities NLNOG to publish a subset of the bulk whois data in the convenient format (JSON) for operational purposes. The ARIN WHOIS (CIDR, OriginAS) tuples can be downloaded in JSON format here: http://irrexplorer.nlnog.net/static/dumps/arin-whois-originas.json.bz2

Because of the JSON dump, the ARIN WHOIS data can now be easily consumed by software programs. For example, the JSON file is now loaded into IRR Explorer as can be seen here: http://irrexplorer.nlnog.net/search/AS22512 You can see the 'arin-whois' column which lists what ASN(s) are authorized to announce the blocks (this, in addition to what is signaled in IRR or RPKI).

The novel thing here is that JSON file not only allows you to look up an OriginAS using the IP prefix as a lookup key, but the reverse can now also be done: lookup what IP prefixes an ASN is allowed to originate (based on ARIN WHOIS data).

Deployment Experience YYCIX

At this point you may be wondering - what does any of the above have to do with an Internet Exchange in Alberta, Canada (https://www.yycix.ca/) or a python-based IXP Route Server management software from Italian origins (http://arouteserver.readthedocs.io/en/latest/) ? :-)

As an experiment to explore real world use of the ARIN WHOIS data and prove its value, I worked with Pier Carlo Chiodi (arouteserver) and Theo de Raadt (YYCIX) to consume the ARIN WHOIS data as an additional source in the prefix filter generation process governing the YYCIX route servers. The YYCIX route servers see roughly 80,000 prefixes.

The results are fantastic: ~ 1,700 IPv4 prefixes that were previously rejected by the YYCIX route servers (because no IRR route object exists), are now accepted because those announcements can be verified against data from ARIN's WHOIS registry. This resolved roughly 23% of invalid path announcements sent to the YYCIX route servers.

Deployment Experience NTT

Based on the above positive results, starting today, NTT is also accepting ARIN WHOIS OriginAS information in conjunction with IRR route objects. Our implementation fetches the ARIN WHOIS data, transforms it into RPSL format, and imports it into our IRRd instance at rr.ntt.net as IRR objects. This way we don't need to update our toolchain to make use of this new data source. An example is here:

job@vurt:~$ whois -h rr.ntt.net -- "-sARIN-WHOIS"
descr: NET-204-209-252-0-1
origin: AS22512
remarks: This route object represents authoritative data retrieved from ARIN's WHOIS service.
remarks: The original data can be found here: https://whois.arin.net/rest/net/NET-204-209-252-0-1
remarks: This route object is the result of an automated WHOIS-to-IRR conversion process.
mnt-by: MAINT-JOB
changed: job at ntt.net 20090220
source: ARIN-WHOIS

NTT also observed a substantial number (similar to YYCIX) of BGP announcements from its customers that were previously rejected because of the lack of an IRR object, but now are validated via ARIN WHOIS.


It is great to be able to offer network operators a choice: either register your BGP announcements as route objects in RPSL format in IRR, or use the ARIN WHOIS web interface, (or both) - either way, as IP transit carrier, we can now pick up your attestations in an automated fashion. This which improves accuracy and reduces red tape! :)

Hopefully more carriers and IXPs will embrace the ARIN WHOIS data source in their automation toolchain. The code & procedures to make use of this source are open. I'm happy to help you both on-list and off-list.



Job Snijders

Internet Architecture at NTT, director NLNOG, vice president PeeringDB, art director at OpenBSD, IETF