AS204997 FIRSTBYTE-AS FIRST SERVER LIMITED

FIRSTBYTE-AS FIRST SERVER LIMITED · registered in the United Kingdom

IPv4 addresses16,12832 prefixes · <0.001% of announced IPv4

Rank in United Kingdom#216largest network in GB by IPv4 space, of 2,074 · 0.02% of GB

Rank worldwide#7,143of 79,396 networks with IPv4

IPv616 x /4811 prefixes

CountryUnited Kingdom2,261 ASNs registered there

Open AS204997 in ASN lookup Look up an IP in this network (45.144.64.1) All networks in United Kingdom

IPv4 prefixes

All 32 prefixes, in address order.

45.144.64.0/22
46.17.104.0/24
91.217.81.0/24
104.128.132.0/24
104.128.136.0/23
104.128.140.0/23
135.136.180.0/24
135.136.188.0/24
135.136.191.0/24
139.28.222.0/23
147.78.64.0/22
157.228.134.0/23
157.228.136.0/23
157.228.190.0/24
178.253.38.0/23
178.253.44.0/23
185.17.3.0/24
185.104.248.0/23
185.139.68.0/22
185.174.138.0/24
185.180.231.0/24
185.188.182.0/23
185.189.12.0/22
185.195.24.0/22
185.204.0.0/24
185.204.2.0/23
185.212.148.0/24
185.244.172.0/23
185.252.146.0/23
185.255.132.0/22
193.109.78.0/23
195.66.114.0/24

IPv6 prefixes

All 11 prefixes.

2a00:e462:ffff::/48
2a04:5200:fb01::/48
2a04:5200:fb02::/48
2a04:5200:ff00::/48
2a04:5200:ff10::/48
2a04:5200:fff1::/48
2a04:5200:fff2::/47
2a04:5200:fff4::/46
2a04:5200:fff8::/47
2a04:5200:ffff::/48
2a0c:5d00:3001::/48

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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