Prefix Fetcher

Prefix Fetcher is a Go-based tool for fetching country-specific IP prefixes from BGP data. Dynamically fetches ASN lists from Regional Internet Registry (RIR) delegated files and filters BGP prefixes accordingly.

Features

• Dynamic ASN Fetching: Automatically downloads the latest ASN allocations from RIR delegated files
  • Iran (IR): Uses RIPE NCC delegated data
  • China (CN): Uses APNIC delegated data
  • Russia (RU): Uses RIPE NCC delegated data
• Comprehensive Coverage: Fetches from all RIRs for complete ASN discovery
• BGP Data: Fetches IP prefixes from bgp.tools
• IPv4 /24 Blocks: Converts IPv4 prefixes to /24 blocks for efficient processing
• IPv6 Preservation: Keeps IPv6 prefixes in their original format
• Clean & Simple: No caching, fresh data on every run
• Automatic retry logic with exponential backoff
• Duplicate removal: Automatically deduplicates ASNs found across multiple RIRs

Prerequisites

• Go (>=1.24)

Build

1. Clone the repository:

   git clone https://github.com/compassvpn/prefix-fetcher.git
   cd prefix-fetcher

2. Build the application:

   go build -o prefix-fetcher

Usage

./prefix-fetcher [OPTIONS]

Available Options

Option	Description
--fetch-ir	Fetch Iranian IP prefixes
--fetch-cn	Fetch Chinese IP prefixes
--fetch-ru	Fetch Russian IP prefixes
-h, --help	Show help information

Examples

• Fetch Iranian IP prefixes:

  ./prefix-fetcher --fetch-ir

• Fetch Chinese IP prefixes:

  ./prefix-fetcher --fetch-cn

• Fetch Russian IP prefixes:

  ./prefix-fetcher --fetch-ru

• Fetch multiple countries:

  ./prefix-fetcher --fetch-ir --fetch-cn --fetch-ru

• Show help:

  ./prefix-fetcher --help

Output Files

The tool generates country-specific prefix files:

Iranian prefixes:

• ir_prefixes_v4.txt - IPv4 prefixes as /24 blocks
• ir_prefixes_v6.txt - IPv6 prefixes

Chinese prefixes:

• cn_prefixes_v4.txt - IPv4 prefixes as /24 blocks
• cn_prefixes_v6.txt - IPv6 prefixes

Russian prefixes:

• ru_prefixes_v4.txt - IPv4 prefixes as /24 blocks
• ru_prefixes_v6.txt - IPv6 prefixes

How It Works

1. Fetches ASN Lists: Downloads the latest ASN allocations from all RIRs for comprehensive coverage:
   • Iran: Primary coverage from RIPE NCC, with additional checks across all RIRs
   • China: Primary coverage from APNIC, with additional checks across all RIRs
   • Russia: Primary coverage from RIPE NCC, with additional checks across all RIRs
2. Downloads BGP Data: Fetches the complete BGP routing table from bgp.tools
3. Filters by ASN: Keeps only prefixes from the dynamically fetched ASN lists
4. Processes IPv4: Converts IPv4 prefixes to /24 blocks for consistency
5. Sorts and Saves: Outputs clean, sorted prefix lists to text files

Data Sources

• RIR Delegated Files:
  • Iran: RIPE NCC (+ all other RIRs)
  • China: APNIC (+ all other RIRs)
  • Russia: RIPE NCC (+ all other RIRs)
• BGP Data: bgp.tools

License

This project is licensed under the MIT License.

Contributions

Contributions are welcome! Feel free to fork the repository and submit a pull request.