Vetted researchers run experiments on Ark, a coordinated, CAIDA-managed platform with a Python API. Researchers in Europe and North America have used it to census anycast, reveal MPLS tunnels, time RPKI propagation, and probe Encrypted Client Hello. Yours could be next.
From the papers
Each dot is a city with a currently reporting Ark vantage point; larger dots host more nodes. Positions come from the live monitor feed. Interactive map and node list.
A daily census of anycast prefixes on the Internet. Ark runs the latency follow-up used to enumerate and geolocate anycast sites, chosen for its reliability, well-documented vantage-point locations, geographic coverage, and Python API. Results are published daily on GitHub.
About 250 IPv4 and 150 IPv6 Ark vantage points (September 2025), daily since June 2024
Traced 13,735 anycast /24 prefixes from 274 Ark vantage points to detect and geolocate remote-peering links at exchange points. Remote peering is widespread but mostly connects networks close to the exchange; the truly remote cases often lead to long detours and steer users to a farther anycast site than the nearest one.
274 Ark vantage points in 178 networks, 3 million traceroutes
The first large-scale test of traceroute-based anycast site enumeration against the latency-based iGreedy method, on about 14,000 anycast-census prefixes. Traceroute enumerates and geolocates slightly better but overestimates site counts and, even optimized, costs about four times the probes.
274 Ark vantage points in 66 countries, 3.4 million traceroutes
Started as the Anycast-GEO prototype at the GMI-AIMS-5 hackathon, February 2025.
Uses scamper on 130 Ark vantage points to snoop the caches of four public DNS resolvers, counting the distinct caches that hold a malicious domain as a lower bound on how many users looked it up.
130 Ark vantage points driven through scamper
Started as the DNS-RTA prototype at the GMI-AIMS-5 hackathon, February 2025.
Watches ROA changes at the RIPE repository and traceroutes each affected prefix from Ark every three minutes for an hour. In preliminary results, changes out of the invalid state reach half the vantage points in 9 to 12 minutes; changes into it take 27 to 42, at least an order of magnitude slower than plain BGP.
283 Ark vantage points in 193 networks, 24,886 ROA transitions over three months
Started as the TracerouteTrigger prototype at the GMI-AIMS-5 hackathon, February 2025.
Pulled RPKI-invalid prefixes from IYP and traced them from Ark. Only 26% of traceroutes to invalid prefixes reached the destination versus 50% for valid ones, and most invalid targets had longer paths and higher RTT.
Reimplemented the TNT tunnel-revelation method as PyTNT on scamper's Python bindings and analyzed traceroutes to every routed IPv4 /24 (about 11.9 million), spread across all 262 Ark vantage points. Found about 20% fewer MPLS tunnels than in 2019, while invisible tunnels remain as common a share as before; public clouds are now three of the ten networks with the most routers seen in MPLS tunnels.
262 Ark vantage points, about 12 million /24s
Traced the team's VMs across regions of four cloud providers from Ark and loaded the paths into a graph database to find which Ark monitors sit within five responsive hops of a cloud region (shown for DigitalOcean).
A probing method that finds ECH deployments without relying on configurations published in DNS, revealing a large, previously undiscovered Meta deployment that is not advertised in DNS. Residential Ark nodes measured TLS handshake delay with and without ECH after CAIDA extended the Ark firmware at the authors' request.
37 residential Ark nodes; CAIDA extended the Ark firmware for ECH
Each node in a network or country Ark does not yet reach gives researchers a vantage point Ark could not offer before. Hosting takes a Raspberry Pi, a 1U server, or a modest virtual server, about 35 kbps of outgoing traffic per measurement, and occasional remote hands.