PTR Zone Generator

This Python script automatically generates a reverse DNS (PTR) zone file for IPv4 ranges.
It’s designed for system administrators, ISPs, or network engineers who manage their own DNS servers.

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🚀 Features

• Supports multiple IP range formats:
  • 10.11.12.1-25 → range from .1 to .25
  • 110.11.12.0/24 → CIDR notation
  • 10.11.12.$ → expands to .1 through .254
• Customizable domain and nameservers
• Automatically generates the correct reverse zone name (db.12.11.10.in-addr.arpa)
• Clean FQDN output (no quoted names)
• Timestamp-based SOA serial

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🧩 Requirements

• Python 3.7+
• No external dependencies required

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💻 Usage

python3 generate_ptrs.py \
  --domain example.com \
  --ns1 ns1.example.com \
  --ns2 ns2.example.com \
  --range 10.11.12.1-255

This will generate a file named:

db.12.11.10.in-addr.arpa.fqdn

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🧾 Example Output

$TTL 3600
@   IN  SOA ns1.example.com. hostmaster.example.com. (
        2025100801 ; Serial
        3600       ; Refresh
        1800       ; Retry
        1209600    ; Expire
        86400 )    ; Minimum TTL
;
    IN  NS  ns1.example.com.
    IN  NS  ns2.example.com.

1   IN  PTR  10-11-12-1.example.com.
2   IN  PTR  10-11-12-2.example.com.
3   IN  PTR  10-11-12-3.example.com.
4   IN  PTR  10-11-12-4.example.com.
5   IN  PTR  10-11-12-5.example.com.
...
255 IN  PTR  10-11-12-255.example.com.

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📂 Output Files

• db.<reversed-zone>.fqdn → clean version ready to import into DNS servers such as Technitium or BIND.

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🧠 Notes

• The script uses the system timezone for the SOA serial.
• If you regenerate the same file later, the serial automatically updates.
• Fully compatible with Technitium DNS Server, BIND, and PowerDNS.

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