NANOG, We would like to inform you of an experiment to evaluate alternatives for speeding up adoption of BGP route origin validation (research paper with details [A]). Our plan is to announce prefix 184.164.224.0/24 with a valid standards-compliant unassigned BGP attribute from routers operated by the PEERING testbed [B, C]. The attribute will have flags 0xe0 (optional transitive [rfc4271, S4.3]), type 0xff (reserved for development), and size 0x20 (256bits). Our collaborators recently ran an equivalent experiment with no complaints or known issues [A], and so we do not anticipate any arising. Back in 2010, an experiment using unassigned attributes by RIPE and Duke University caused disruption in Internet routing due to a bug in Cisco routers [D, CVE-2010-3035]. Since then, this and other similar bugs have been patched [e.g., CVE-2013-6051], and new BGP attributes have been assigned (BGPsec-path) and adopted (large communities). We have successfully tested propagation of the announcements on Cisco IOS-based routers running versions 12.2(33)SRA and 15.3(1)S, Quagga 0.99.23.1 and 1.1.1, as well as BIRD 1.4.5 and 1.6.3. We plan to announce 184.164.224.0/24 from 8 PEERING locations for a predefined period of 15 minutes starting 14:30 GMT, from Monday to Thursday, between the 7th and 22nd of January, 2019 (full schedule and locations [E]). We will stop the experiment immediately in case any issues arise. Although we do not expect the experiment to cause disruption, we welcome feedback on its safety and especially on how to make it safer. We can be reached at disco-experiment@googlegroups.com. Amir Herzberg, University of Connecticut Ethan Katz-Bassett, Columbia University Haya Shulman, Fraunhofer SIT Ítalo Cunha, Universidade Federal de Minas Gerais Michael Schapira, Hebrew University of Jerusalem Tomas Hlavacek, Fraunhofer SIT Yossi Gilad, MIT [A] https://conferences.sigcomm.org/hotnets/2018/program.html [B] http://peering.usc.edu [C] https://goo.gl/AFR1Cn [D] https://labs.ripe.net/Members/erik/ripe-ncc-and-duke-university-bgp-experime... [E] https://goo.gl/nJhmx1