Intro to i6.shark#

i6.shark is an IPv6 proxy server that allows you to make HTTP requests from randomly generated IPv6 addresses in a /48 subnet. This is the proxy currently powering Wyzie Subs in production.

A /48 subnet has 1,208,925,819,614,629,174,706,176 (1.2 x 10^24) IPv6 addresses, making it virtually impossible to block through traditional IP banning. Using a single subnet means those who really want to block you can block your ASN address, so be careful with that.

Features#

• Random IPv6 Generation: Creates random IPv6 addresses from your /48 prefix for each request
• HTTP Methods: GET, HEAD and POST; anything else gets a 405
• HMAC-SHA256 Authentication: Secure API key authentication using user-agent based tokens
• Intelligent IP Pool Management: Automatic IP rotation with configurable pool size. Smart IP lifecycle management. Per-IP request counting. Unused IP cleanup based on inactivity threshold.
• Safe Request Handling: Only an allowlist of request headers is forwarded, never the API token or Cloudflare and forwarding headers. Destinations on loopback, private, link-local and other internal networks (including the server's own addresses) are refused, after DNS and on every redirect (at most 5). Support for multiple URL parameter formats. Optional fallback to system default IP.
• Automatic Maintenance: Periodic IP pool flushing. Subnet validation and cleanup. Connection pooling and keepalive optimization.
• High Performance: Concurrent request handling with buffer pooling. Configurable timeouts and connection limits. Efficient IPv6 address management.
• Debug Mode: Detailed logging for troubleshooting and monitoring

Requirements#

• Go 1.22 or higher
• Linux/Unix system with IPv6 support (preferably Ubuntu)
• Root privileges (for port 80 binding and IPv6 manipulation)
• IPv6 /48 subnet allocation from your hosting provider

Hosting Providers#

The following providers are known to offer /48 IPv6 subnets: