Summary

  • Mistral Compute operates its own autonomous system, AS209952, registered to Mistral Compute Holding SAS, with an Open peering policy and a single 400 Gbps public peering port at the 'nine' internet exchange (PeeringDB, ix.report, bgp.he.net).
  • The site's dedicated grid supply — a ~10 km, 225 kV underground line from RTE's Des Loges substation to Eclairion's Bruyères-le-Châtel substation — was still in civil works on 3 July 2026, after Mistral's stated end-of-June 2026 operating target (RTE project page, RTE Ollainville letter, 3 July 2026).
  • No operator or trade source names a transit provider for the site; Eclairion's materials mention only unspecified "connectivity" (Eclairion site page, Eclairion FAQ).

Mistral Compute is the infrastructure arm of Mistral AI, built around a financed fleet of 13,800 NVIDIA GB300 GPUs and 44 MW of powered capacity at Eclairion's Bruyères-le-Châtel site south of Paris, announced with $830 million of debt on 30 March 2026 (Data Center Dynamics). Prior coverage resolved what the money buys and who lends it. It did not resolve the two physical interfaces that determine whether that fleet can serve traffic: the network edge and the electrical feed.

The network edge. Mistral Compute Holding SAS holds AS209952. PeeringDB lists it with an Open peering policy — no ratio requirement, no contract requirement — and one public peering row: a 400 Gbps port at the exchange "nine", with IPv4 185.1.14.83 and IPv6 2001:7f8:12e::20:9952:1, marked Operational, last updated 23 April 2026 (PeeringDB). Two independent third-party sources corroborate the presence: ix.report ranks AS209952 as participant 7 at nine with one route-server port and 400 Gbps connected capacity, alongside carriers such as Free SAS and OVHcloud (ix.report), and Hurricane Electric's exchange table lists the same AS with the same addresses (bgp.he.net).

Three caveats temper that picture. First, PeeringDB data is self-reported by the operator. Second, neither ix.report nor bgp.he.net ties the port to a specific facility — a 400 Gbps port at a Paris exchange point does not establish that a Bruyères-le-Châtel cage terminates there. Third, one port is a thin network edge for a cluster marketed as Europe's largest AI compute deployment; hyperscale training fleets typically need multi-site, multi-carrier diversity. The public record shows no second exchange presence, no IX at the site itself, and no named transit contracts.

The electrical feed. RTE, France's transmission operator, is building a new underground 225 kV line of roughly 10 km between Eclairion's own substation at Bruyères-le-Châtel and RTE's Des Loges substation at La Norville, crossing five communes, with works scheduled progressively from June 2025 to October 2026 (RTE). A local information letter dated 3 July 2026 shows civil works in Ollainville still running from 1 June to 15 July 2026 (RTE letter) — after the end-of-June 2026 start Mistral announced with its financing (Data Center Dynamics). The RTE documents describe construction, not energisation: no service date, no conformity acceptance, no metered load is published.

This sits alongside the pattern the execution audit documented: third-party registry Scrutica labels the facility "Operational" while simultaneously stating that no operational date was published (Scrutica). The grid record contradicts a reading that full dedicated supply was in service by end-June 2026; it is consistent with staged or interim supply, but the public record does not say which.

What is genuinely new. Mistral Compute owning an AS is a structural signal: a company that a year ago bought GPUs through intermediaries now maintains its own routing identity and a peering posture intended to attract settlement-free interconnection. That the AS exists with a single 400 Gbps port — while the site's dedicated 225 kV feed was still being trenched in July 2026 — sketches the real sequence of deployment: routing presence first, physical delivery later.

Sources for the financing and grid record: HPCwire, Datacenter Paris, DatacenterPlus, RTE, document 8.3.6, BTW on power capacity, BTW on the grid connection.