Reverse DNS Lookup (PTR)
Resolve the Pointer (PTR) DNS registry mapping associated with a target IP address.
Reverse DNS Lookup & PTR Records Tool
Welcome to the ultimate network diagnostic dashboard. If you are wondering what is a DNS (Domain Name System) or specifically need to perform a reverse dns lookup, you are in the right spot. While a standard IP Address Lookup or a query to lookup website names turns a domain into an IP address, a reverse DNS (rDNS) lookup uses a Pointer Record (PTR) to resolve an IP back to a hostname. You can also trace hostnames using our Hostname Lookup, run full records scans on our DNS Record Resolver, or query registrar details on our WHOIS Lookup.
Checking Your Basic Network Details
Before diving into complex routing, many users simply need to check their basic connection. If your first thought is "what is my ip?" or "where i can find my ip," our My IP Dashboard immediately displays your my internet protocol address.
Whether you search for my ip, whatismyip, whats my ip, or even repeat it out of frustration like "whats my ip whats my ip whats my ip," the answer is simple. Our system answers questions ranging from "what is my ip address", "whats my ip address", and "what's my ip" to "where is my address ip." We also test for IPv6 connectivity (via test-ipv6 or an ip6 check) and perform a rapid dns leak check to ensure your traffic is secure. Check your network routing anomalies and identify potential leaks by performing a Proxy / VPN Check.
Email Deliverability & Blacklist Checks
A properly configured PTR record is critical for email sending. Without it, your emails might bounce or face an outlook sending delay or outlook delay delivery. Keeping up with email deliverability news today shows that major providers heavily rely on rDNS to fight spam. If your mail server IP lacks a PTR record, you might quickly learn the blacklist meaning.
Users often ask "what does blacklisted mean", "what does it mean blacklisted", or look for a blacklist definition (or blacklisted meaning). In short, it means your IP has been flagged by spam filters. You can check if your IP address is flagged on major blocklists like Spamhaus, SORBS, or Spamcop using our dedicated Blacklist Check tool.
Our tool suite also includes a message header analyzer to verify spamassassin scores, check domain scores, and inspect protocols like DKIM (dkm) and MTA-STS management. For tracing suspicious emails, utilize our Trace Email Sender, or parse HTTP request data with our HTTP Request Headers viewer. If you are trying to find where a server's mail exchange is routed, you can query mx where or mx google. Secure your systems further by scanning open ports using our Port Scanner, scanning data exposures with our Breach Check or Personal Data Scan, and looking up phone country codes with our Phone Lookup.
Subnet Calculators & CIDR Notation
For network engineers, allocating IP blocks efficiently is essential. Our platform provides a comprehensive subnet calculator suite. Whether you call it an ip subnet calculator, a network subnet calculator, or a subnet mask calculator, these tools help you break down networks using CIDR notation and determine your exact cidr range. Benchmarking latency is easy with our Speed Test page too.
Here are some of the specialized calculations you can perform:
| Feature | Common Search Queries Supported |
|---|---|
| Basic IP Calculators | ip calculator, network calculator, ip address calculator, subnet calc, online subnet calculator, online ip subnet calculator, calculator ip subnetting, subnetting ip calculator, networking subnet calculator, subnetting ip address calculator, kalkulator ip address, network subnet calc, ip address subnet calculator |
| Masks & Conversions | netmask calculator, calculator for subnet mask, ip netmask converter, ip to subnet converter, subnet to ip range converter, ip range calculator subnet mask, subnet mask calculate ip address, binary calc, calculator subnet ip |
| CIDR Blocks | /30 subnet, /29 network mask, /27 subnet, /22 subnet mask, inter prefix |
Additional Tools and Lookups
Beyond standard lookups, our platform handles port scanning (like checking port status or ip port https) and advanced queries like a .info whois lookup or a whois usa. We often see users inputting typos or random search strings into lookup tools. Our intelligent parser successfully handles variations like:
- IP Typos: whatismyipaddress, whatsmyip, myip, my i, my i[, my.ip, myip.com, myipadress, ny ip, my ip.com, what ip, what my ip, where my ip, my ip my ip my ip, what is my
- International & Niche Queries: เช็คไอพี (Thai for check IP), queries for specific TLDs like .mx, or custom Dorks like inurl:baidu.com.
- Raw Lookups: We even process raw lookups like lookup ip address with ip lookup or parse string anomalies (e.g., 400/500, afac, aznudd, time breaker mask all masks, gmai.com, worldtranslation.org, and various domain tests like thepiratebay.com and allporncomic com).
Frequently Asked Questions (FAQ)
A reverse DNS lookup queries the Domain Name System to determine the hostname associated with an IP address, utilizing a PTR record. It works as the direct opposite of a standard forward A record lookup.
If your IP is blacklisted, it has been identified as a source of spam or malicious activity by email filtering organizations. Your outgoing emails will likely be blocked or sent to the recipient's spam folder until the issue is resolved and you request delisting.
When designing a network, an ip address subnet calculator helps you divide a larger network into smaller, manageable sub-networks. This improves security and performance, allowing you to easily find the correct cidr range, ip lookup limits, and broadcast addresses.
Yes. If your mail server sends an email to an Outlook or Microsoft 365 address and you do not have a valid PTR record, the receiving server will view your message with high suspicion, often delaying it or dropping it entirely.
Video Guide: Understanding PTR Records
Check out this video for a visual breakdown of how PTR records work and why setting up reverse DNS is crucial for your network and email deliverability: What is a PTR Record? (reverse DNS).