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AS1280 Internet Systems Consortium, Inc.

ISC-AS-1280 - Internet Systems Consortium, Inc. · registered in the United States

IPv4 addresses23,29620 prefixes · <0.001% of announced IPv4
Rank in United States#2,005largest network in US by IPv4 space, of 18,338 · <0.01% of US
Rank worldwide#5,666of 79,396 networks with IPv4
IPv665,516 x /4833 prefixes
CountryUnited States18,679 ASNs registered there
Open AS1280 in ASN lookup Look up an IP in this network (149.20.1.1) All networks in United States

IPv4 prefixes

All 20 prefixes, in address order.

  • 149.20.1.0/24
  • 149.20.6.0/23
  • 149.20.8.0/24
  • 149.20.10.0/24
  • 149.20.12.0/22
  • 149.20.16.0/20
  • 149.20.32.0/20
  • 149.20.48.0/21
  • 149.20.56.0/24
  • 149.20.58.0/23
  • 149.20.60.0/22
  • 149.20.64.0/23
  • 149.20.72.0/21
  • 149.20.80.0/21
  • 149.20.88.0/24
  • 149.20.90.0/23
  • 149.20.92.0/22
  • 192.111.107.0/24
  • 192.158.252.0/24
  • 204.152.184.0/21

IPv6 prefixes

All 33 prefixes.

  • 2001:4f8::/47
  • 2001:4f8:3::/48
  • 2001:4f8:4::/48
  • 2001:4f8:5::/48
  • 2001:4f8:6::/47
  • 2001:4f8:8::/48
  • 2001:4f8:a::/48
  • 2001:4f8:c::/46
  • 2001:4f8:10::/48
  • 2001:4f8:12::/47
  • 2001:4f8:14::/46
  • 2001:4f8:18::/45
  • 2001:4f8:20::/43
  • 2001:4f8:40::/42
  • 2001:4f8:80::/41
  • 2001:4f8:100::/40
  • 2001:4f8:200::/39
  • 2001:4f8:400::/38
  • 2001:4f8:800::/37
  • 2001:4f8:1000::/36
  • 2001:4f8:2000::/35
  • 2001:4f8:4000::/34
  • 2001:4f8:8000::/34
  • 2001:4f8:c000::/35
  • 2001:4f8:e000::/36
  • 2001:4f8:f000::/37
  • 2001:4f8:f800::/38
  • 2001:4f8:fc00::/39
  • 2001:4f8:fe10::/44
  • 2001:4f8:fe20::/43
  • 2001:4f8:fe40::/42
  • 2001:4f8:fe80::/41
  • 2001:4f8:ff00::/40

Other ASNs named Internet Systems Consortium, Inc.

6 other networks use the same organisation name; together with AS1280 they announce 37,120 IPv4 addresses.

ASNNameIPv4 addresses
AS30133ISC-F-AS - Internet Systems Consortium, Inc. US9,984
AS27321ISC-F-AS - Internet Systems Consortium, Inc. US2,048
AS30132ISC-F-AS - Internet Systems Consortium, Inc. US768
AS3557ISC-AS - Internet Systems Consortium, Inc. US512
AS33071ISC-F-AS - Internet Systems Consortium, Inc. US256
AS23713ISC-SEL1 - Internet Systems Consortium, Inc. KR256

Similar-sized networks in United States

ASNNameIPv4 addresses
AS62654#2002 MENLO-SECURITY - MENLO SECURITY, INC.23,552
AS64249#2003 ENDOFFICE - Charles River Operation23,296
AS27288#2004 DPCHICO-1 - Digital Path23,296
AS62651#2006 NETPROTECT-DP - Strong Technology, LLC.23,296
AS10355#2007 DSCGA - Digital Service Consultants23,296
AS19605#2008 3RC - 3 Rivers Telephone Cooperative, Inc.23,296

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