AS55 University of Pennsylvania

UPENN - University of Pennsylvania · registered in the United States

IPv4 addresses261,88811 prefixes · 0.008% of announced IPv4

Rank in United States#271largest network in US by IPv4 space, of 18,338 · 0.02% of US

Rank worldwide#915of 79,396 networks with IPv4

IPv665,535 x /4816 prefixes

CountryUnited States18,679 ASNs registered there

Open AS55 in ASN lookup Look up an IP in this network (128.91.0.1) All networks in United States

IPv4 prefixes

All 11 prefixes, in address order.

128.91.0.0/16
130.91.0.0/16
158.130.0.0/16
165.123.0.0/17
165.123.128.0/18
165.123.194.0/23
165.123.196.0/22
165.123.200.0/21
165.123.208.0/20
165.123.224.0/19
192.84.2.0/24

IPv6 prefixes

All 16 prefixes.

2607:f470::/34
2607:f470:4000::/36
2607:f470:5001::/48
2607:f470:5002::/47
2607:f470:5004::/46
2607:f470:5008::/45
2607:f470:5010::/44
2607:f470:5020::/43
2607:f470:5040::/42
2607:f470:5080::/41
2607:f470:5100::/40
2607:f470:5200::/39
2607:f470:5400::/38
2607:f470:5800::/37
2607:f470:6000::/35
2607:f470:8000::/33

Other ASNs named University of Pennsylvania

2 other networks use the same organisation name; together with AS55 they announce 262,656 IPv4 addresses.

ASNNameIPv4 addresses

AS400653UPENN-WHARTON-SF - University of Pennsylvania US512

AS69UPENN-NETWORK-LAB - University of Pennsylvania US256

Similar-sized networks in United States

ASNNameIPv4 addresses

AS292#268 ESNET-WEST - ESnet262,144

AS11377#269 SENDGRID - SendGrid, Inc.262,144

AS26662#270 XEROX-WV - XEROX CORPORATION262,144

AS2048#272 LANET-1 - State of Louisiana Office of Technology Services261,696

AS4454#273 TNET-AS - State of Tennessee260,864

AS6360#274 UNIVHAWAII - University of Hawaii255,234

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