Observed topology
AS2500 WIDE-BB WIDE Project
Transit
Upstream networks
Networks observed carrying traffic for AS2500: 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 |
|---|---|---|---|---|
| AS2914 | NTT America, Inc. | Transit | IPv4 IPv6 | 85 |
| AS17676 | SoftBank Corp. | Mobile | IPv4 IPv6 | 55 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 51 |
| AS7660 | Asia Pacific Advanced Network - Japan | Unclassified | IPv4 IPv6 | 13 |
| AS141682 | APIDT Infrastructure Pty Ltd | Unclassified | IPv4 | 6 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 4 |
| AS9002 | RETN Limited | Unclassified | IPv4 | 3 |
| AS2497 | Internet Initiative Japan Inc. | Unclassified | IPv4 | 3 |
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.
Transit
Downstream networks
Networks for which AS2500 was observed as the last hop before the origin, meaning it appears to provide them transit.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS23799 | National Defense Academy | Unclassified | IPv4 | 244 |
| AS63783 | Chiba University of Commerce | Unclassified | IPv4 | 122 |
| AS55384 | Japan Advanced Institute of Science and Technology | Unclassified | IPv4 IPv6 | 95 |
| AS4690 | WIDE Project | Unclassified | IPv4 IPv6 | 94 |
| AS141682 | APIDT Infrastructure Pty Ltd | Unclassified | IPv4 IPv6 | 88 |
| AS17932 | Japan Advanced Institute of Science and Technology | Unclassified | IPv4 IPv6 | 80 |
| AS4717 | WIDE Project | Education | IPv4 IPv6 | 38 |
| AS131158 | Nara Institute of Science and Technology, National University Corporation | Unclassified | IPv4 IPv6 | 38 |
| AS2515 | Japan Network Information Center | Unclassified | IPv4 IPv6 | 25 |
| AS38635 | Keio University | Unclassified | IPv4 IPv6 | 22 |
| AS2501 | The University of Tokyo | Education | IPv4 | 16 |
| AS4777 | Asia Pacific Network Information Centre | Unclassified | IPv4 IPv6 | 12 |
| AS4718 | Cyber Kansai Project | Unclassified | IPv4 IPv6 | 11 |
| AS7667 | KDDI Research, Inc. | Unclassified | IPv4 | 7 |
| AS23634 | WIDE Project | Unclassified | IPv4 | 5 |
| AS7660 | Asia Pacific Advanced Network - Japan | Unclassified | IPv4 | 4 |
| AS9367 | Institute of Science Tokyo | Education | IPv4 | 3 |
| AS7500 | WIDE Project | Hosting | IPv4 | 1 |
Adjacency
Adjacent networks
Every AS seen directly next to AS2500 in a routing path, in either direction.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS17676 | SoftBank Corp. | Mobile | IPv4 IPv6 | 504 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 250 |
| AS23799 | National Defense Academy | Unclassified | IPv4 | 244 |
| AS2914 | NTT America, Inc. | Transit | IPv4 IPv6 | 192 |
| AS7660 | Asia Pacific Advanced Network - Japan | Unclassified | IPv4 IPv6 | 123 |
| AS63783 | Chiba University of Commerce | Unclassified | IPv4 | 122 |
| AS141682 | APIDT Infrastructure Pty Ltd | Unclassified | IPv4 IPv6 | 110 |
| AS55384 | Japan Advanced Institute of Science and Technology | Unclassified | IPv4 IPv6 | 95 |
| AS4690 | WIDE Project | Unclassified | IPv4 IPv6 | 94 |
| AS17932 | Japan Advanced Institute of Science and Technology | Unclassified | IPv4 IPv6 | 80 |
| AS4717 | WIDE Project | Education | IPv4 IPv6 | 38 |
| AS131158 | Nara Institute of Science and Technology, National University Corporation | Unclassified | IPv4 IPv6 | 38 |
| AS2515 | Japan Network Information Center | Unclassified | IPv4 IPv6 | 25 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 23 |
| AS38635 | Keio University | Unclassified | IPv4 IPv6 | 22 |
| AS2501 | The University of Tokyo | Education | IPv4 | 16 |
| AS9002 | RETN Limited | Unclassified | IPv4 | 13 |
| AS7530 | BroadBand Tower, Inc. | Hosting | IPv6 | 12 |
| AS2497 | Internet Initiative Japan Inc. | Unclassified | IPv4 | 12 |
| AS4777 | Asia Pacific Network Information Centre | Unclassified | IPv4 IPv6 | 12 |
| AS4718 | Cyber Kansai Project | Unclassified | IPv4 IPv6 | 11 |
| AS7667 | KDDI Research, Inc. | Unclassified | IPv4 | 7 |
| AS2516 | KDDI CORPORATION | Mobile | IPv4 | 5 |
| AS23634 | WIDE Project | Unclassified | IPv4 | 5 |
| AS2907 | Research Organization of Information and Systems, National Institute of Informatics | Unclassified | IPv4 | 5 |
| AS9367 | Institute of Science Tokyo | Education | IPv4 | 3 |
| AS7500 | WIDE Project | Hosting | IPv4 | 1 |
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.
Interconnection
Exchange presence
Internet exchanges where Packet Clearing House has a port recorded for AS2500, largest fabric first. An exchange is shared switching where networks interconnect directly rather than paying a transit provider to carry traffic between them, so turning up at one is a deliberate choice about how this network wants to be reached. Each name opens that exchange's own page, with its peering LANs and every other network recorded on it. Recorded at 3 exchanges across 2 countries and 1 region.
| Exchange | Location | Their address | Member ports |
|---|---|---|---|
| BroadBand Internet eXchange Tokyo | Tokyo, Japan | 101.203.90.75 | 359 |
| BroadBand Internet eXchange Singapore | Singapore, Singapore | 103.231.152.253 | 151 |
| Network Service Provider IXP (Distributed IX in Edo) | Tokyo, Japan | 202.249.2.14 | 28 |
Unlike the tables above, this is recorded rather than inferred. An address on a peering LAN is at that exchange by definition. Two carve-outs all the same. Member ports counts every participant at the exchange, not this network's ports, so read it as a size proxy. And an absent exchange means PCH has no record of it, not that the network is not there.
Provenance
Where this comes from
Derived from routing tables collected at 2026-08-08 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.02M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.
Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.
Exchange presence comes from a separate dataset: the directory collected 2026-08-09 by Packet Clearing House (https://www.pch.net/ixp/data), covering 1,327 exchanges and 93,164 recorded member ports, licensed CC BY-NC-SA 3.0.
PeeringDB is the better-known directory and is deliberately not the source here: its acceptable-use policy forbids the bulk storage this needs. The two answer different questions anyway. PeeringDB reports what an operator declares about itself; this reports what PCH has recorded.