Routing security
AS2501 UTNET The University of Tokyo
Education ARIN
Announcements
What this network originates
Every prefix observed with AS2501 as its origin, checked against RPKI and the IRR. Problems sort first.
| Prefix | RPKI | IRR | Vantage points |
|---|---|---|---|
| 130.69.0.0/16 | No ROA | IRR | 55 |
| 133.11.0.0/16 | No ROA | IRR | 55 |
| 157.82.0.0/16 | No ROA | IRR | 55 |
| 192.51.208.0/20 | No ROA | IRR | 55 |
| 2404:d540::/32 | No ROA | IRR | 30 |
| 2404:d540:1::/48 | No ROA | IRR | 29 |
RPKI · ROAs
Route origin authorisations
Signed statements by address holders that AS2501 may originate these prefixes, up to the maximum length shown.
No ROA names this AS as an authorised origin.
ROA-based and RPKI-valid-only prefix lists for routers are on asn.ipinfo.app.
RPKI · ASPA
Declared transit providers
No ASPA record This network has not published an ASPA object. ASPA lets a network sign the list of its transit providers, so routers can reject paths that route through anyone else (route leaks). Only a few thousand networks publish one so far, so its absence is normal.
IRR
Registered route objects
Route objects naming AS2501 as origin, across RADb, the RIR registries, ALTDB and NTTCOM. Objects that are registered but not announced come first: a stale object lets anyone who can spoof this origin through an IRR-built filter.
| Prefix | Source | Description | Maintainer | Changed | Routing |
|---|---|---|---|---|---|
| 192.31.118.0/24 | RADB | The University of Tokyo | MAINT-AS2500 | 2023-11-13 | Not announced |
| 130.69.0.0/16 | RADB | The University of Tokyo | MAINT-AS2500 | 2023-11-13 | Announced |
| 133.11.0.0/16 | RADB | The University of Tokyo | MAINT-AS2500 | 2023-11-13 | Announced |
| 157.82.0.0/16 | RADB | The University of Tokyo | MAINT-AS2500 | 2023-11-13 | Announced |
| 192.51.208.0/20 | RADB | JERNET | MAINT-AS2500 | 2023-11-13 | Announced |
| 2404:d540::/32 | RADB | The University of Tokyo | MAINT-AS2501 | 2025-06-25 | Announced |
| 2404:d540:1::/48 | RADB | UTNET IPv6 Prefix | MAINT-AS2500 | 2023-11-13 | Announced |
IRR
AS-sets
The as-set is what upstreams expand to build this network's customer filter. Sets that list AS2501 directly show who expects to carry it.
| AS-set | Where | Relationship |
|---|---|---|
AS-2500-2914 | RADB | Lists AS2501 as a direct member |
AS-2500ARCSTAR | NTTCOM | Lists AS2501 as a direct member |
AS-BBIX-T | RADB | Lists AS2501 as a direct member |
AS-BBIX-T-V6 | RADB | Lists AS2501 as a direct member |
AS-IIJ | RADB | Lists AS2501 as a direct member |
AS-IIJ6 | RADB | Lists AS2501 as a direct member |
AS-KDDDMPEER | RADB | Lists AS2501 as a direct member |
AS-WIDE | RADB | Lists AS2501 as a direct member |
AS20965:AS-FROM-TEIN-TO-GEANT | RIPE | Lists AS2501 as a direct member |
AS2497:AS-IIJ | RADB | Lists AS2501 as a direct member |
AS2497:AS-IIJ6 | RADB | Lists AS2501 as a direct member |
AS2500:AS-TRANSIT | RADB | Lists AS2501 as a direct member |
RPKI from rpki-client, validated 2026-10-22 12:01 UTC. IRR from ARIN, RADB, RIPE, ALTDB, APNIC, LACNIC, NTTCOM, AFRINIC, collected 2026-10-22. Cross-check on bgp.he.net.