How IP Address Lookup Works

This tool performs a local analysis using standard IP rules and DNS resolution. It does not require extra software: you paste an IP address (IPv4 or IPv6) or a hostname, choose an output format, and generate a structured report you can copy or download.

Step-by-step

• 1) Enter a query: Paste an IPv4/IPv6 address or a hostname such as example.com.
• 2) Choose behavior: Optionally enable hostname resolution (A/AAAA) and reverse DNS lookups.
• 3) Generate: The tool validates the format, runs classification checks, and collects any available DNS details.
• 4) Review the report: See whether the address is public, private, loopback, link-local, multicast, or otherwise reserved.
• 5) Export: Copy the output or download it as a text file for tickets, reports, or documentation.

Key Features

IPv4 and IPv6 validation

The tool checks whether the input is a syntactically valid IP address. For hostnames, it verifies the hostname format and can resolve it to one or more A/AAAA records, helping you confirm what an application actually points to.

Public vs private and special-use detection

Not all IPs are routable on the public internet. The report highlights private ranges (such as RFC1918 IPv4 networks), loopback, link-local, and other special-use blocks so you can quickly tell whether an address should be visible externally.

Human-readable networking notes

Instead of returning a single “valid/invalid” result, the output includes short explanations that are useful for helpdesk tickets and incident timelines—especially when diagnosing VPN issues, NAT behavior, or internal routing problems.

Reverse DNS (rDNS) lookup

If rDNS is enabled, the tool attempts to obtain a PTR-style hostname for the IP. This can help associate an address with a service name, datacenter label, or device record. Keep in mind that rDNS depends on how the owner configured DNS, so results can be empty or generic.

Text or JSON output

Choose a clean text report for quick sharing, or JSON for parsing and automation. JSON output is handy when you want to paste the result into scripts, dashboards, or a SIEM note without reformatting.

Use Cases

• Incident response: Classify suspicious IPs (public, private, reserved) before escalating to blocking or enrichment workflows.
• IT support tickets: Confirm whether a user is reporting an internal address, a VPN-assigned address, or a public endpoint.
• DNS troubleshooting: Resolve a hostname to IPs and compare the results with what your CDN, load balancer, or firewall expects.
• Server inventory: Use rDNS output as a quick hint for identifying old hosts, legacy services, or provider naming conventions.
• Network documentation: Produce consistent, copy-ready summaries when writing runbooks or change requests.
• Learning and training: Explore IPv4 vs IPv6, special-use ranges, and common address categories with practical examples.

Whether you are validating a single address or quickly checking what a hostname resolves to, the tool keeps the workflow simple: paste, generate, and share.

Optimization Tips

Use the right input type for the question

If you are troubleshooting an application URL, paste the hostname and enable resolution so you can see the actual A/AAAA targets. If you are investigating a log entry, paste the raw IP and enable rDNS to get a best-effort name.

Compare multiple resolved addresses

Some domains return many IPs (round-robin DNS, CDNs, dual-stack deployments). Generate JSON output to capture the full list and keep a record of which addresses were returned at the time of investigation.

Remember that DNS can be incomplete

Missing rDNS does not mean an IP is malicious; it often means the operator did not set PTR records. Treat DNS results as helpful hints and corroborate them with your internal inventory and security tooling.

FAQ