Upstream networks
AS21737 SPRINGNET2-NET
Unclassified RIPE
Transit
Upstream networks
Networks observed carrying traffic for AS21737: the AS immediately before it in a routing path. Ranked by how many paths showed the relationship, which reflects how widely it is used, not how much traffic crosses it.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS1299 | Arelion Sweden AB | Transit | IPv4 IPv6 | 225 |
| AS3356 | Level 3 Parent, LLC | Transit | IPv4 IPv6 | 212 |
| AS174 | Cogent Communications, LLC | Transit | IPv4 | 172 |
| AS34927 | iFog GmbH | Hosting | IPv6 | 1 |
Inferred from path position, not from any declaration by either party. A network appearing here is carrying these routes; whether that is a paid transit arrangement, a backup, or something else is not something routing data can tell you.
Derived from routing tables collected at 2026-10-12 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.21M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.