https://github.com/povzayd/ptrex
PTRex is a Bash script for performing reverse DNS (PTR) lookups on single IPs, CIDR ranges, or IP lists. It uses getent hosts, supports parallel execution for speed, and filters results to show only successful lookups.
https://github.com/povzayd/ptrex
dnsx-alternate info-gathering osint ptr ptr-analysis ptr-lookup website-pentesting
Last synced: 11 months ago
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PTRex is a Bash script for performing reverse DNS (PTR) lookups on single IPs, CIDR ranges, or IP lists. It uses getent hosts, supports parallel execution for speed, and filters results to show only successful lookups.
- Host: GitHub
- URL: https://github.com/povzayd/ptrex
- Owner: povzayd
- Created: 2025-03-23T13:10:41.000Z (11 months ago)
- Default Branch: main
- Last Pushed: 2025-03-24T08:21:06.000Z (11 months ago)
- Last Synced: 2025-03-24T09:32:13.792Z (11 months ago)
- Topics: dnsx-alternate, info-gathering, osint, ptr, ptr-analysis, ptr-lookup, website-pentesting
- Language: Shell
- Homepage:
- Size: 14.6 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
🔍 PTRex 🦖 Reverse DNS Lookup Script
This Bash script performs reverse DNS (PTR) lookups on a given IP, CIDR range, or a list of IPs from a file. It efficiently resolves hostnames using `getent hosts`, tracks progress, and runs queries in parallel for speed.
🚀 Features
✅ Accepts a single IP, CIDR range, or file with multiple IPs
✅ Uses `getent hosts` for reverse DNS (PTR) lookups 🔄
✅ Parallel execution (up to 50 requests at a time) for faster results ⚡
✅ Tracks progress dynamically 📊
✅ Filters and outputs only successful PTR lookups (hostnames only) 🛠
🚀 Installation
Ensure you have `prips` `git` installed for CIDR expansion:
```
bash
sudo apt install prips git
git clone https://github.com/povzayd/ptrex.git
cd ptrex && chmod +x *
./ptrex
```
🚀 Usage
Run the script and enter an IP, CIDR range, or a file path when prompted:
```
bash
./ptrex
```
🚀 Global Package
Making this shell script global will alow you to execute this in any directory
For that just move the file `ptrex` to `bin` or `sbin`
```
bash
mv ptrex /usr/bin
or
mv ptrex /usr/sbin
```
*📌 Example Inputs*
1️⃣ Single IP: `8.8.8.8`
2️⃣ CIDR Range: `192.168.1.0/24`
3️⃣ File with IPs: `/path/to/ips.txt`
*📜 Output Example*
```
[+] Processing IPs from file: ips.txt
[+] Requests made: 12 / 100
[+] Completed!
✅ -> example.com
✅ -> mail.google.com
✅ -> somehost.net
```
🔎 How It Works
1️⃣ User Input
- Prompts user to enter an IP, CIDR, or file path
- Determines input type (single IP, CIDR, or file)
2️⃣ IP Expansion (if CIDR)
- Uses `prips` to generate a list of IPs from the CIDR range
3️⃣ Parallel Reverse DNS Lookups
- Uses `getent hosts` to fetch PTR records 🕵️
- Runs up to 50 parallel lookups using `xargs -P 50`
- Displays live progress updates
4️⃣ Output Processing
- Saves only successful hostname lookups 🎯
- Hides IPs, displaying hostnames only
5️⃣ Cleanup
- Deletes temporary files after execution 🧹
⚠️ Notes
⚡ Only successful lookups (resolved hostnames) are displayed
⚡ Parallel execution speeds up large queries
⚡ If `prips` is missing, CIDR expansion will fail
🔮 Future Improvements
✨ Add logging for debugging
✨ Implement timeouts for slow DNS responses
✨ Support custom concurrency levels
This script is great for security assessments, network mapping, and passive reconnaissance when identifying hostnames associated with an IP range. 🌍
---
*PLEASE NOTE THAT THE SCRIPT GIVES OUTPUT IN THE FORM OF
```
-> some.pointer.record.abc.com
```
IF YOU WANT TO REMOVE IT FROM YOUR TXT FILE JUST USE THE COMMAND
```
sed -i 's/->//g' file.txt
```
THIS WILL REMOVE `->` FROM EACH & EVERY LINE OF YOUR FILE.