All-in-one IPv4 / IPv6 Address Lookup

AS9009（M247 Europe SRL） (Amazon.com, Inc.) manages the 51.146.220.0/22 prefix block (approximately 1024 addresses) in the Datacenter / Cloud category. AS9009 independently controls its routing policy, peering relationships and IP allocation — Amazon.com, Inc. is directly responsible for traffic to and from addresses in the 51.146.220.0/22 block. The IP 51.146.221.251 resides in United States Colorado Tokyo (timezone Asia/Tokyo); its position within this block determines routing behavior and connectivity characteristics.

No reverse DNS (PTR) record is configured, which is common for dynamically assigned or CGNAT'd addresses but limits reverse verification capability. Proxy and VPN exit nodes often omit PTR records to reduce attribution surface, which is consistent with the anonymization purpose of this address.

Identified as a VPN / proxy exit, this IP is commonly used for masking the origin of traffic. Content delivery and geo-restriction systems frequently treat such addresses with elevated scrutiny. Traffic from VPN/proxy exits requires heightened scrutiny; consider CAPTCHA or secondary verification for sensitive operations.

Recommendation: apply conditional access for 51.146.221.251. VPN/proxy traffic is not inherently malicious — many legitimate users rely on VPNs for privacy — but for geo-restricted content or fraud-sensitive flows, require additional verification before granting access.

This IP is classified as a proxy/VPN exit — assume that any request from it originates from an unknown real location. For fraud-sensitive workflows (payments, account creation), request secondary verification. For non-sensitive browsing, consider allowing access but logging the IP for audit.