UDP checks from French nodes test reachability of UDP-based services from two distinct French networks. From Gravelines, OVH's network carries UDP traffic on direct peered paths to most European destinations, so latency should be close to the ICMP ping baseline. UDP probes from Paris via DataCamp take different transit routes and can reveal whether UDP-specific filtering is applied differently across providers.

OVH operates a significant anti-DDoS infrastructure that can interfere with UDP probe behaviour. When OVH's VAC (Vacuuming Anti-DDoS Cloud) is active on a target IP, UDP traffic may be scrubbed or shaped. If UDP checks from Gravelines show unexpected loss or latency spikes for a target also hosted on OVH, it's worth checking whether OVH's mitigation is engaged on the destination — this can happen automatically when traffic patterns exceed OVH's detection thresholds.

For testing DNS server reachability from France, UDP checks from the Gravelines node are particularly useful. OVH hosts a large number of DNS servers and resolvers internally, and a UDP probe to port 53 from the OVH network closely mimics what a French OVH customer's DNS query would look like. If your authoritative DNS doesn't respond to the Gravelines probe, French OVH-hosted clients may be experiencing resolution failures.

France has two nodes on this platform covering two distinct parts of the country and two very different network environments. The Gravelines node runs on AS16276, which is OVH SAS — the largest hosting provider in Europe by server count, headquartered in Roubaix in northern France. The Paris node runs on AS212238, operated by DataCamp Limited, a provider that focuses on bulletproof-adjacent hosting and operates in multiple European jurisdictions.

OVH's network is one of the more interesting in Europe. The company operates its own submarine cable and maintains extensive private fibre between its data centres in Roubaix, Gravelines, Strasbourg, and beyond. Gravelines is a purpose-built data centre campus about 40km west of Dunkirk, close to the Channel Tunnel corridor. OVH peers directly at most major European IXPs and carries a significant portion of its own transit, which means routing from Gravelines can look quite different from what you'd see on a standard transit-dependent host.

France-IX is the main French internet exchange, operating peering nodes in Paris, Lyon, and Marseille. The Paris node at France-IX handles the bulk of domestic and international peering for French networks. Paris sits roughly equidistant between London and Frankfurt, and the raw fibre distances translate to consistent latency: London to Paris typically runs 12ms, Paris to Frankfurt around 11ms, making Paris a natural midpoint for traffic flowing across the northern European backbone.

The southern France-IX nodes in Lyon and Marseille are important for Mediterranean and southern European traffic. Marseille in particular is a major submarine cable landing point — several cables connecting Europe to the Middle East, Africa, and Asia come ashore there. For traffic heading to those regions, routing via Marseille can be significantly faster than going north to Paris or Amsterdam first.

DataCamp Limited in Paris operates on a network that serves a range of hosting use cases, some of which attract abuse-focused traffic. This means the Paris node's source IP may behave differently from OVH when hitting targets with aggressive firewall rules or reputation-based blocking. Testing from both French nodes side by side is useful: if a target responds to OVH but not DataCamp, the issue is IP reputation or ASN-level blocking, not a general France connectivity problem.