Observed topology
AS3661 ERX-CUHKNET The Chinese University of Hong Kong
Education APNIC
Transit
Upstream networks
Networks observed carrying traffic for AS3661: 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 |
|---|---|---|---|---|
| AS3662 | Joint Universities Computer Centre Limited | Education | IPv4 | 328 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 120 |
| AS137207 | Joint Universities Computer Centre Limited | Unclassified | IPv4 IPv6 | 38 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 7 |
| AS4635 | Hong Kong Internet Exchange--Route Server 1 | Unclassified | IPv4 | 5 |
| AS8359 | MTS PJSC | Mobile | IPv4 | 5 |
| AS55720 | Gigabit Hosting Sdn Bhd | Hosting | IPv4 | 5 |
Transit
Downstream networks
Networks for which AS3661 was observed as the last hop before the origin, meaning it appears to provide them transit.
No downstream observed. This network does not appear to carry transit for anyone.
Adjacency
Adjacent networks
Every AS seen directly next to AS3661 in a routing path, in either direction.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS3662 | Joint Universities Computer Centre Limited | Education | IPv4 | 328 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 120 |
| AS137207 | Joint Universities Computer Centre Limited | Unclassified | IPv4 IPv6 | 38 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 7 |
| AS4635 | Hong Kong Internet Exchange--Route Server 1 | Unclassified | IPv4 | 5 |
| AS8359 | MTS PJSC | Mobile | IPv4 | 5 |
| AS55720 | Gigabit Hosting Sdn Bhd | Hosting | IPv4 | 5 |
Provenance
Where this comes from
Derived from routing tables collected at 2026-10-30 10:00 UTC by route-views2,rrc00, as seen from 76 BGP vantage points across 74.49M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.
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. Adjacency is not the same as peering. Being next to each other in a path covers paid transit, settlement-free peering and customer connections alike, and routing data cannot distinguish them. Treat this as "these networks exchange routes", nothing more specific.
Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.