51.161.65.210📋 Copy

# IP Intelligence Briefing: 51.161.65.210/32

## Executive Summary

The IP address 51.161.65.210 is a moderate-risk (score 40) hosting endpoint operated within OVH infrastructure in Montreal, QC. The address belongs to CIDR block 51.161.65.0/24, classified as high-abuse with 0.6953 abuse density. The IP resolves to ahostname proxy-ca011-san210.ahrefs.net under the ahrefs.net domain. No active services or open ports were detected during scanning.

## Ownership and Infrastructure

• ASN: 16276 (OVH)
• Organization: Dmytro, Ahrefs Pte Ltd
• Network Name: OVH-CUST-281059690
• Classification: Hosting infrastructure
• Geolocation: Montreal, Quebec, Canada (CA)
• BGP Prefix: 51.161.0.0/17
• Route Stability: Route changes recorded (isRouteStable: false)

## Network Context and Abuse Indicators

The address resides within a /24 subnet (51.161.65.0/24) exhibiting high abuse density. Neighborhood analysis identified 256 total sibling IPs, with 209 active and 178 flagged as threats. The subnet shows a risk distribution of 99 medium-risk neighbors and 1 low-risk neighbor. The target IP carries an inherited subnet risk score of 27.

Threat intelligence indicates:

• DNSBL listings: 1 out of 8 threat feeds
• Operator score: 0.2174 (Minimal)
• No known attacker, spam source, or Tor exit node indicators
• No active threat campaigns or certificate matches

## Service and DNS Profile

DNS resolution confirmed the hostname proxy-ca011-san210.ahrefs.net. The address has no open ports or running services. No TLS certificates, HTTP banners, or service fingerprints were detected. Email authentication records (SPF, DMARC) are not configured. Control plane analysis shows DNSSEC validation enabled with CAA records present.

## Historical Observation

Analysis captured 19 signal observations over the monitoring period. One threat observation was recorded. The IP is not flagged as persistently malicious. Recent observations consistently report high abuse classification and moderate-risk scoring.

## Recommended Actions

Based on the risk profile, the following actions are recommended:

Firewall Blocking Rules:

• iptables: `iptables -A INPUT -s 51.161.65.210 -j DROP`
• nftables: `nft add rule inet filter input ip saddr 51.161.65.210 drop`
• nginx: `deny 51.161.65.210;`
• pfSense: `51.161.65.210/32`

WAF Integration:

• Cloudflare WAF: Block IP 51.161.65.210 with expression `ip.src eq 51.161.65.210`
• AWS WAF: Add 51.161.65.210/32 to rule set with description "IPDebrief risk 40"

## Intelligence Assessment

The IP address represents a moderate-risk endpoint within a high-abuse OVH hosting subnet. The hostname suggests legitimate proxy infrastructure (ahrefs.net), but the subnet's abuse density warrants caution. Blocking is recommended for defensive posture, particularly given the 178 threat-sibling IPs within the /24. No active malicious indicators were detected, but the environment requires monitoring for potential abuse.

This summary was generated by AI and may contain inaccuracies. Verify critical details independently.