203.6.72.0/21 CIDR Lookup — 2.0K IPs

Reputation · trust score

A transparent 0–100 signal. Every entity starts at a neutral baseline of 65; threat-intel blocklists, exposure, reverse-DNS, routing and allocation each adjust it up or down. Higher is more trustworthy.

76/100

Moderate

How this score is built

Baseline (neutral) 65
Long-established allocation (32y) +6
Has a reverse-DNS (PTR) record +5
Trust score 76 / 100

Experimental · trust-vectors model v1.1.0 — a transparent heuristic, not a definitive verdict. How it works →

Ranges inside 203.6.72.0/21

CIDR	IPs	Organization	ASN	Country
203.6.76.0/22	1.0K	UUNET Japan Limited	AS9466	AU
203.6.76.0/22	1.0K	UUNET Japan Limited	AS9466	AU
203.6.72.0/23	512	UUNET Japan Limited	AS9466	AU
203.6.72.0/23	512	UUNET Japan Limited	AS9466	AU
203.6.74.0/24	256	Cloudflare London, LLC	AS209242	AU
203.6.74.0/24	256	Cloudflare London, LLC	AS209242	AU
203.6.75.0/24	256	UUNET Japan Limited	AS9466	AU
203.6.75.0/24	256	UUNET Japan Limited	AS9466	AU

Geolocation

First 256 of 2,048 IP addresses in 203.6.72.0/21

203.6.72.0 203.6.72.1 203.6.72.2 203.6.72.3 203.6.72.4 203.6.72.5 203.6.72.6 203.6.72.7 203.6.72.8 203.6.72.9 203.6.72.10 203.6.72.11 203.6.72.12 203.6.72.13 203.6.72.14 203.6.72.15 203.6.72.16 203.6.72.17 203.6.72.18 203.6.72.19 203.6.72.20 203.6.72.21 203.6.72.22 203.6.72.23 203.6.72.24 203.6.72.25 203.6.72.26 203.6.72.27 203.6.72.28 203.6.72.29 203.6.72.30 203.6.72.31 203.6.72.32 203.6.72.33 203.6.72.34 203.6.72.35 203.6.72.36 203.6.72.37 203.6.72.38 203.6.72.39 203.6.72.40 203.6.72.41 203.6.72.42 203.6.72.43 203.6.72.44 203.6.72.45 203.6.72.46 203.6.72.47 203.6.72.48 203.6.72.49 203.6.72.50 203.6.72.51 203.6.72.52 203.6.72.53 203.6.72.54 203.6.72.55 203.6.72.56 203.6.72.57 203.6.72.58 203.6.72.59 203.6.72.60 203.6.72.61 203.6.72.62 203.6.72.63 203.6.72.64 203.6.72.65 203.6.72.66 203.6.72.67 203.6.72.68 203.6.72.69 203.6.72.70 203.6.72.71 203.6.72.72 203.6.72.73 203.6.72.74 203.6.72.75 203.6.72.76 203.6.72.77 203.6.72.78 203.6.72.79 203.6.72.80 203.6.72.81 203.6.72.82 203.6.72.83 203.6.72.84 203.6.72.85 203.6.72.86 203.6.72.87 203.6.72.88 203.6.72.89 203.6.72.90 203.6.72.91 203.6.72.92 203.6.72.93 203.6.72.94 203.6.72.95 203.6.72.96 203.6.72.97 203.6.72.98 203.6.72.99 203.6.72.100 203.6.72.101 203.6.72.102 203.6.72.103 203.6.72.104 203.6.72.105 203.6.72.106 203.6.72.107 203.6.72.108 203.6.72.109 203.6.72.110 203.6.72.111 203.6.72.112 203.6.72.113 203.6.72.114 203.6.72.115 203.6.72.116 203.6.72.117 203.6.72.118 203.6.72.119 203.6.72.120 203.6.72.121 203.6.72.122 203.6.72.123 203.6.72.124 203.6.72.125 203.6.72.126 203.6.72.127 203.6.72.128 203.6.72.129 203.6.72.130 203.6.72.131 203.6.72.132 203.6.72.133 203.6.72.134 203.6.72.135 203.6.72.136 203.6.72.137 203.6.72.138 203.6.72.139 203.6.72.140 203.6.72.141 203.6.72.142 203.6.72.143 203.6.72.144 203.6.72.145 203.6.72.146 203.6.72.147 203.6.72.148 203.6.72.149 203.6.72.150 203.6.72.151 203.6.72.152 203.6.72.153 203.6.72.154 203.6.72.155 203.6.72.156 203.6.72.157 203.6.72.158 203.6.72.159 203.6.72.160 203.6.72.161 203.6.72.162 203.6.72.163 203.6.72.164 203.6.72.165 203.6.72.166 203.6.72.167 203.6.72.168 203.6.72.169 203.6.72.170 203.6.72.171 203.6.72.172 203.6.72.173 203.6.72.174 203.6.72.175 203.6.72.176 203.6.72.177 203.6.72.178 203.6.72.179 203.6.72.180 203.6.72.181 203.6.72.182 203.6.72.183 203.6.72.184 203.6.72.185 203.6.72.186 203.6.72.187 203.6.72.188 203.6.72.189 203.6.72.190 203.6.72.191 203.6.72.192 203.6.72.193 203.6.72.194 203.6.72.195 203.6.72.196 203.6.72.197 203.6.72.198 203.6.72.199 203.6.72.200 203.6.72.201 203.6.72.202 203.6.72.203 203.6.72.204 203.6.72.205 203.6.72.206 203.6.72.207 203.6.72.208 203.6.72.209 203.6.72.210 203.6.72.211 203.6.72.212 203.6.72.213 203.6.72.214 203.6.72.215 203.6.72.216 203.6.72.217 203.6.72.218 203.6.72.219 203.6.72.220 203.6.72.221 203.6.72.222 203.6.72.223 203.6.72.224 203.6.72.225 203.6.72.226 203.6.72.227 203.6.72.228 203.6.72.229 203.6.72.230 203.6.72.231 203.6.72.232 203.6.72.233 203.6.72.234 203.6.72.235 203.6.72.236 203.6.72.237 203.6.72.238 203.6.72.239 203.6.72.240 203.6.72.241 203.6.72.242 203.6.72.243 203.6.72.244 203.6.72.245 203.6.72.246 203.6.72.247 203.6.72.248 203.6.72.249 203.6.72.250 203.6.72.251 203.6.72.252 203.6.72.253 203.6.72.254 203.6.72.255 + 1.8K more (range too large to list inline)

BGP Routing

Live BGP anomalies →

This block is announced in BGP, observed across our RIPE RIS collectors.

Announced prefix

203.6.72.0/21

Origin AS

AS9466

Announcement samples

4,363

Last seen

2026-07-23 04:51:47

Frequently Asked Questions

What is 203.6.72.0/21?

203.6.72.0/21 is a CIDR network block containing 2,048 IPv4 addresses (from 203.6.72.0 to 203.6.79.255). CIDR notation combines an IP address with a prefix length to define a range of addresses.

Who owns the 203.6.72.0/21 network?

The 203.6.72.0/21 range is allocated to an unknown organization from Australia.