IP Due Diligence Report
Enter any IPv4 address or subnet to get a comprehensive pre-purchase analysis — blacklist status, BGP visibility, RPKI validation, proxy/VPN/Tor detection, and more. A free tool by IPv4Center.
Supports single IPs and subnets up to /16. Blacklist check limited to /24.
BGP & RPKI
Routing status, AS origin, visibility score, and RPKI validation.
Blacklist Status
Scan results against 100+ DNS-based blacklists.
IP Intelligence
Proxy, VPN, and Tor detection results.
What is IP Due Diligence?
IP Due Diligence is a comprehensive pre-purchase analysis tool for IPv4 addresses. It combines blacklist checking, BGP visibility analysis, RPKI validation, and IP intelligence (proxy/VPN/Tor detection) into a single report. Whether you are buying, leasing, or transferring IPv4 addresses, this tool helps you identify potential issues before committing.
How Does It Work?
Enter any IPv4 address or CIDR prefix and our system runs multiple checks simultaneously: BGP routing analysis via RIPE Stat, blacklist scanning against 100+ DNSBLs, RPKI validation, and IP quality assessment. Results are compiled into a comprehensive report you can download as PDF.
Why Run Due Diligence Before Buying IPv4?
IPv4 addresses can carry history from previous owners — blacklist entries, proxy/VPN associations, stale routing objects, or even hijacking records. Without proper due diligence, you risk acquiring address space that causes deliverability issues, security blocks, or routing problems. This free tool helps you make informed decisions before you buy IPv4 on our marketplace.
Why IP Due Diligence Matters Before Purchase
IP due diligence is the process of investigating the history, reputation, and technical status of an IPv4 address block before completing a purchase or lease transaction. Failing to perform due diligence exposes buyers to significant financial risk — acquiring blacklisted addresses can cost weeks of remediation effort and result in 20-40% loss of email deliverability during the cleanup period.
Abuse history follows an IP address permanently across ownership changes. Blacklist providers, content delivery networks, and major email providers maintain historical records that do not automatically reset when registration changes hands. A /24 block with active Spamhaus SBL listings may require 30-90 days of delisting effort after transfer, during which the addresses are effectively unusable for email or web hosting.
The financial impact extends beyond direct remediation costs. Organizations that deploy blacklisted IP space face customer-facing service disruptions, damaged sender reputation that takes months to rebuild, and potential contractual penalties from SLA violations. In 2026, the average cost of deploying a contaminated /24 block without prior due diligence is estimated at $3,000-8,000 in lost productivity and remediation services.
What to Check Before Buying IPv4 Addresses
BGP history analysis reveals whether a prefix has been announced consistently, hijacked, or used in route leaks. Check the prefix's origin AS history over the past 12 months using RIPEstat or BGPStream — frequent origin changes or announcements from unrelated ASNs indicate potential hijacking or instability that may persist in routing databases and trigger anomaly detection systems.
Blacklist status must be verified across all major DNSBLs including Spamhaus (SBL, XBL, PBL, DBL), Barracuda BRBL, SpamCop, SORBS, and UCEPROTECT. A comprehensive scan checks every /32 address in the target block. Even a single listed IP in a /24 can indicate broader abuse patterns that will attract scrutiny from receiving mail systems.
RPKI (Resource Public Key Infrastructure) status verification confirms whether valid ROA (Route Origin Authorization) objects exist for the prefix and whether they match the expected origin AS. Invalid or missing RPKI records cause route filtering by networks that enforce RPKI validation — approximately 40% of global IPv4 routes are now covered by ROAs as of 2026. Additionally, verify geolocation accuracy, abuse contact responsiveness, and whether the block appears in proxy/VPN/Tor detection databases.
What's Included in the Report
Frequently Asked Questions
Common questions about IP Due Diligence reports.
Yes, IP Due Diligence is completely free to use. You can generate reports for any IPv4 address regardless of whether you are buying from IPv4Center.com or another provider.
BGP data comes from RIPE Stat (Routing Information Service). Blacklist data is scanned against 100+ DNS-based blacklists. IP intelligence data (proxy/VPN/Tor) is available for addresses in our marketplace database.
Reports are stored for 7 days. You can download the PDF at any time during this period. After 7 days, you can generate a new report.
Yes, you can check any IPv4 address or subnet up to /16. The IP does not need to be listed on IPv4Center.com.
If a prefix is not announced in BGP, it means no AS number is currently advertising this prefix to the global routing table. This is normal for unused address space and does not indicate a problem.