AS2501 The University of Tokyo

UTnet - The University of Tokyo · registered in Japan

IPv4 addresses200,7044 prefixes · 0.006% of announced IPv4

Rank in Japan#44largest network in JP by IPv4 space, of 724 · 0.12% of JP

Rank worldwide#1,078of 79,396 networks with IPv4

IPv61 x /32 (65,536 x /48)16 prefixes

CountryJapan745 ASNs registered there

Open AS2501 in ASN lookup Look up an IP in this network (130.69.0.1) All networks in Japan

IPv4 prefixes

All 4 prefixes, in address order.

130.69.0.0/16
133.11.0.0/16
157.82.0.0/16
192.51.208.0/20

IPv6 prefixes

All 16 prefixes.

2404:d540::/47
2404:d540:2::/47
2404:d540:4::/46
2404:d540:8::/45
2404:d540:10::/44
2404:d540:20::/43
2404:d540:40::/42
2404:d540:80::/41
2404:d540:100::/40
2404:d540:200::/39
2404:d540:400::/38
2404:d540:800::/37
2404:d540:1000::/36
2404:d540:2000::/35
2404:d540:4000::/34
2404:d540:8000::/33

Similar-sized networks in Japan

ASNNameIPv4 addresses

AS2522#41 PPP-EXP - Japan Network Information Center229,120

AS2506#42 SuperCSI - NTT business Solutions corporation214,272

AS7687#43 D-CRUISENET - TOYOTA SYSTEMS CORPORATION200,960

AS4686#45 BEKKOAME - BEKKOAME INTERNET INC.200,448

AS9354#46 TDNC - Community Network Center Inc.200,448

AS23793#47 AIST - National Institute of Advanced Industrial Science and Technology199,936

IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources