$ query “AS2501” --type=asn → 1 result(s)
AS2501 · UTNET
The University of Tokyo
AS2501 is run by The University of Tokyo and is an educational/research stub network, established in Japan. The system announces a solid 200 704 IPv4 addresses, including a /16, and supports IPv6. The bulk of its IP address space is in Japan.
Basic Information
- Country
- 🇯🇵 Japan
- Category
- Education/Research
- Network Role
- Stub Network
- Data Origin
- Authoritative — Metadata from authoritative RIR registry (ARIN, RIPE, APNIC, etc.)
- Last Changed
- March 04, 2026
- Last Seen
- May 01, 2026 (active)
Prefix Summary
- IPv4 Prefixes (raw / aggregated)
- 4 / 4
- IPv6 Prefixes (raw / aggregated)
- 2 / 1
- IPv4 Addresses
- 200 704
- Largest IPv4 Prefix
- /16 (65 536 addresses)
- Largest IPv6 Prefix
- /32
- Geolocated Countries
- 🇯🇵 Japan (335 872 IPs)
- Prefix Changed
- March 04, 2026
Reputation
- Reputation
- Good — 1 flagged IPs out of 200 704 total (0.00%)
Connectivity Summary
- Upstream Providers
- 2 upstreams providing transit
- Degree
- 2 unique BGP neighbors
- Reach
- 0 networks in customer cone
Upstream Providers (2)
Prefix Lists
IPv4 Prefixes (4 total)
- 130.69.0.0/16 (65 536 addresses (/16 prefix))
- 133.11.0.0/16 (65 536 addresses (/16 prefix))
- 157.82.0.0/16 (65 536 addresses (/16 prefix))
- 192.51.208.0/20 (4 096 addresses (/20 prefix))
IPv6 Prefixes (2 total)
- 2404:d540::/32