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AS51561 AS-ICUK ICUK Computing Services Limited

AS-ICUK ICUK Computing Services Limited · registered in the United Kingdom

IPv4 addresses73,21661 prefixes · 0.002% of announced IPv4
Rank in United Kingdom#65largest network in GB by IPv4 space, of 2,074 · 0.11% of GB
Rank worldwide#2,359of 79,396 networks with IPv4
IPv61 x /32 (65,536 x /48)17 prefixes
CountryUnited Kingdom2,261 ASNs registered there
Open AS51561 in ASN lookup Look up an IP in this network (2.56.84.1) All networks in United Kingdom

IPv4 prefixes

All 61 prefixes, in address order.

  • 2.56.84.0/22
  • 5.133.168.0/22
  • 5.254.162.0/23
  • 5.254.164.0/23
  • 37.235.43.0/24
  • 45.93.112.0/22
  • 45.145.86.0/23
  • 46.33.128.0/23
  • 46.33.130.0/24
  • 46.33.131.0/24
  • 46.33.132.0/22
  • 46.33.136.0/21
  • 46.33.144.0/21
  • 46.33.152.0/22
  • 46.33.156.0/24
  • 46.33.157.0/24
  • 46.33.158.0/23
  • 46.102.192.0/23
  • 46.102.194.0/23
  • 46.102.196.0/22
  • 46.102.200.0/21
  • 46.102.208.0/20
  • 46.226.120.0/24
  • 80.95.192.0/20
  • 80.209.128.0/20
  • 80.209.144.0/21
  • 80.209.152.0/22
  • 80.209.156.0/22
  • 80.209.160.0/19
  • 80.247.216.0/24
  • 82.39.142.0/24
  • 89.107.24.0/22
  • 91.233.33.0/24
  • 138.124.128.0/21
  • 138.124.136.0/23
  • 138.124.138.0/24
  • 138.124.139.0/24
  • 138.124.140.0/23
  • 138.124.142.0/24
  • 138.124.143.0/24
  • 185.2.236.0/22
  • 185.32.55.0/24
  • 185.35.148.0/22
  • 185.132.52.0/24
  • 185.137.240.0/24
  • 185.140.16.0/22
  • 185.145.152.0/22
  • 185.152.2.0/24
  • 185.168.10.0/24
  • 185.201.208.0/22
  • 185.234.255.0/24
  • 185.243.62.0/23
  • 185.253.88.0/24
  • 188.211.249.0/24
  • 188.240.160.0/19
  • 193.161.9.0/24
  • 193.161.10.0/24
  • 193.187.0.0/24
  • 194.15.37.0/24
  • 205.157.160.0/19
  • 217.22.12.0/24

IPv6 prefixes

All 17 prefixes.

  • 2a00:b900::/47
  • 2a00:b900:2::/48
  • 2a00:b900:3::/48
  • 2a00:b900:4::/46
  • 2a00:b900:8::/45
  • 2a00:b900:10::/44
  • 2a00:b900:20::/43
  • 2a00:b900:40::/42
  • 2a00:b900:80::/41
  • 2a00:b900:100::/40
  • 2a00:b900:200::/39
  • 2a00:b900:400::/38
  • 2a00:b900:800::/37
  • 2a00:b900:1000::/36
  • 2a00:b900:2000::/35
  • 2a00:b900:4000::/34
  • 2a00:b900:8000::/33

Similar-sized networks in United Kingdom

ASNNameIPv4 addresses
AS61323#62 UKFAST ANS ACADEMY LIMITED80,896
AS16247#63 M247-UK Convergence Group (Wireless) Networks Limited79,872
AS16082#64 SPITFIRE Spitfire Network Services Limited79,872
AS60187#66 LGFL-AS London Grid for Learning Trust71,424
AS21433#67 AccentureFSSC Accenture UK Limited69,888
AS2818#68 BBC BBC69,632

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