How to Fix AI API Failures That Look Like Rate Limits but Are Actually Network Issues

TL;DR

If your OpenAI, Claude, or Gemini API calls are failing with cryptic errors that look like rate limits, the real culprit is often your network — ISP routing, DNS pollution, or TCP RST injection. A real 429 has a JSON body and a Retry-After header; a network failure gives you an empty response, a connection reset, or a timeout. Here's how to tell them apart and fix it systematically.

I spent two frustrating days last month convinced I'd somehow blown through my OpenAI quota. My Python script kept dying with RateLimitError, but the OpenAI dashboard showed I'd barely touched my limits. Sound familiar? If you're working from Southeast Asia, mainland China, or certain parts of the Middle East, this is a surprisingly common trap.

Let me walk you through exactly how I diagnosed it and what I did to fix it.

Real 429 vs. Network Failure — Know the Difference