Observed topology
AS2153 CENIC-2153
Transit
Upstream networks
Networks observed carrying traffic for AS2153: 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 |
|---|---|---|---|---|
| AS11537 | Internet2 | Unclassified | IPv4 IPv6 | 37 |
| AS7575 | Australian Academic and Research Network (AARNet) | Education | IPv4 | 22 |
| AS293 | ESnet | Unclassified | IPv4 | 11 |
| AS2152 | CENIC | Unclassified | IPv4 | 2 |
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 AS2153 was observed as the last hop before the origin, meaning it appears to provide them transit.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS2152 | CENIC | Unclassified | IPv4 IPv6 | 3,219 |
| AS2907 | Research Organization of Information and Systems, National Institute of Informatics | Unclassified | IPv4 | 600 |
| AS668 | United States Department of Defense (DoD) | Business | IPv4 | 191 |
| AS195 | San Diego Supercomputer Center | Unclassified | IPv4 IPv6 | 181 |
| AS6192 | University of California, Davis | Education | IPv4 IPv6 | 105 |
| AS7377 | University of California, San Diego | Education | IPv4 IPv6 | 97 |
| AS52 | University of California, Los Angeles | Unclassified | IPv4 IPv6 | 61 |
| AS46985 | The Regents of the University of California - University of California, San Diego. | Unclassified | IPv4 | 45 |
| AS299 | University of California, Irvine | Unclassified | IPv4 IPv6 | 31 |
| AS31 | California Institute of Technology | Unclassified | IPv4 IPv6 | 31 |
| AS131 | University of California, Santa Barbara | Unclassified | IPv4 | 30 |
| AS293 | ESnet | Unclassified | IPv4 | 27 |
| AS17579 | KISTI | Education | IPv4 | 27 |
| AS26397 | The Regents of the University of California - University of California, San Diego. | Unclassified | IPv4 | 26 |
| AS5653 | University of California San Francisco | Education | IPv4 | 25 |
| AS11096 | FloridaNet | Education | IPv4 | 24 |
| AS40498 | New Mexico Lambda Rail, Inc. | Unclassified | IPv4 | 23 |
| AS32361 | UltraLight | Unclassified | IPv4 | 22 |
| AS11537 | Internet2 | Unclassified | IPv4 | 21 |
| AS257 | Navy Network Information Center (NNIC) | Unclassified | IPv4 | 20 |
| AS32 | Stanford University | Unclassified | IPv4 IPv6 | 16 |
| AS5739 | University of California, Santa Cruz | Education | IPv4 IPv6 | 13 |
| AS396310 | San Diego State University | Unclassified | IPv4 | 12 |
| AS38022 | REANNZ National Research and Education Network | Unclassified | IPv4 | 12 |
| AS6106 | University of California, Riverside | Education | IPv4 IPv6 | 8 |
| AS6360 | University of Hawaii | Education | IPv4 | 7 |
| AS22323 | University of California, Merced | Unclassified | IPv4 | 7 |
| AS7960 | California Polytechnic State University | Education | IPv4 | 6 |
| AS2037 | California State University at Fresno | Unclassified | IPv4 | 6 |
| AS16 | Lawrence Berkeley National Laboratory | Unclassified | IPv4 | 6 |
| AS9 | Carnegie Mellon University | Unclassified | IPv4 | 6 |
| AS7539 | National Center for High-performance Computing | Education | IPv4 | 6 |
| AS396465 | California State University, Sacramento | Unclassified | IPv4 | 6 |
| AS26488 | Santa Clara University | Unclassified | IPv4 | 6 |
| AS46357 | California Polytechnic State University | Unclassified | IPv4 | 5 |
| AS47 | University of Southern California | Unclassified | IPv4 | 3 |
| AS6509 | CANARIE Inc | Education | IPv4 | 2 |
| AS101 | University of Washington | Unclassified | IPv4 | 2 |
| AS24 | National Aeronautics and Space Administration | Unclassified | IPv4 IPv6 | 2 |
Adjacency
Adjacent networks
Every AS seen directly next to AS2153 in a routing path, in either direction.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS2152 | CENIC | Unclassified | IPv4 IPv6 | 26,351 |
| AS11537 | Internet2 | Unclassified | IPv4 IPv6 | 16,990 |
| AS38022 | REANNZ National Research and Education Network | Unclassified | IPv4 IPv6 | 3,308 |
| AS7575 | Australian Academic and Research Network (AARNet) | Education | IPv4 IPv6 | 2,259 |
| AS293 | ESnet | Unclassified | IPv4 | 1,518 |
| AS6509 | CANARIE Inc | Education | IPv4 | 1,130 |
| AS2907 | Research Organization of Information and Systems, National Institute of Informatics | Unclassified | IPv4 IPv6 | 1,071 |
| AS17579 | KISTI | Education | IPv4 | 572 |
| AS567 | Los Nettos | Unclassified | IPv4 | 351 |
| AS195 | San Diego Supercomputer Center | Unclassified | IPv4 IPv6 | 316 |
| AS668 | United States Department of Defense (DoD) | Business | IPv4 | 283 |
| AS11096 | FloridaNet | Education | IPv4 | 272 |
| AS6192 | University of California, Davis | Education | IPv4 IPv6 | 110 |
| AS7377 | University of California, San Diego | Education | IPv4 IPv6 | 97 |
| AS40498 | New Mexico Lambda Rail, Inc. | Unclassified | IPv4 | 64 |
| AS52 | University of California, Los Angeles | Unclassified | IPv4 IPv6 | 61 |
| AS101 | University of Washington | Unclassified | IPv4 | 57 |
| AS7539 | National Center for High-performance Computing | Education | IPv4 | 52 |
| AS46985 | The Regents of the University of California - University of California, San Diego. | Unclassified | IPv4 | 45 |
| AS8075 | Microsoft Corporation | Hosting | IPv4 | 31 |
| AS299 | University of California, Irvine | Unclassified | IPv4 IPv6 | 31 |
| AS31 | California Institute of Technology | Unclassified | IPv4 IPv6 | 31 |
| AS131 | University of California, Santa Barbara | Unclassified | IPv4 | 30 |
| AS26397 | The Regents of the University of California - University of California, San Diego. | Unclassified | IPv4 | 26 |
| AS5653 | University of California San Francisco | Education | IPv4 | 25 |
| AS32361 | UltraLight | Unclassified | IPv4 | 22 |
| AS6360 | University of Hawaii | Education | IPv4 | 21 |
| AS257 | Navy Network Information Center (NNIC) | Unclassified | IPv4 | 20 |
| AS32 | Stanford University | Unclassified | IPv4 IPv6 | 18 |
| AS5739 | University of California, Santa Cruz | Education | IPv4 IPv6 | 13 |
| AS396310 | San Diego State University | Unclassified | IPv4 | 12 |
| AS6106 | University of California, Riverside | Education | IPv4 IPv6 | 8 |
| AS22323 | University of California, Merced | Unclassified | IPv4 | 7 |
| AS26488 | Santa Clara University | Unclassified | IPv4 | 6 |
| AS7960 | California Polytechnic State University | Education | IPv4 | 6 |
| AS16 | Lawrence Berkeley National Laboratory | Unclassified | IPv4 | 6 |
| AS396465 | California State University, Sacramento | Unclassified | IPv4 | 6 |
| AS2037 | California State University at Fresno | Unclassified | IPv4 | 6 |
| AS9 | Carnegie Mellon University | Unclassified | IPv4 | 6 |
| AS46357 | California Polytechnic State University | Unclassified | IPv4 | 5 |
| AS14041 | University Corporation for Atmospheric Research | Education | IPv4 | 3 |
| AS47 | University of Southern California | Unclassified | IPv4 | 3 |
| AS24 | National Aeronautics and Space Administration | Unclassified | IPv4 IPv6 | 3 |
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 AS2153, 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.
No exchange membership on file. That is not the same as peering nowhere: the dataset records what PCH has collected, and many exchanges publish no participant list at all.
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.