The ROUTER_EXTERNAL_TARGET_HANDSHAKE_ERROR error occurs when a connection cannot be successfully established with an external target. This error may result from issues during the SSL handshake process or due to a timeout, and is often attributed to one of the following causes:
- SSL handshake failure: The SSL handshake may fail if the target has an invalid certificate or uses an unsupported Cipher Suite
- Timeout: The error could also be due to a timeout, which might be caused by issues connecting to the target. Note that proxied requests to external targets have a maximum timeout of 120 seconds (2 minutes).
ROUTER_EXTERNAL_TARGET_HANDSHAKE_ERROR:
Unable to establish connection with external target
I'm encountering an error and reviewing the docs at https://vercel.com/docs/errors/ROUTER_EXTERNAL_TARGET_HANDSHAKE_ERROR.md to understand what's happening.
Please help me resolve this by:
1. **Suggest the fix**: Analyze my codebase context and propose what needs to be changed to resolve this error. If you do not have access to my codebase, ask me for the codebase and try to fix the error based on the information you have.
2. **Explain the root cause**: Break down why this error occurred:
- What was the code actually doing vs. what it needed to do?
- What conditions triggered this specific error?
- What misconception or oversight led to this?
3. **Teach the concept**: Help me understand the underlying principle:
- Why does this error exist and what is it protecting me from?
- What's the correct mental model for this concept?
- How does this fit into the broader framework/language design?
4. **Show warning signs**: Help me recognize this pattern in the future:
- What should I look out for that might cause this again?
- Are there similar mistakes I might make in related scenarios?
- What code smells or patterns indicate this issue?
5. **Discuss alternatives**: Explain if there are different valid approaches and their trade-offs
My goal is to fix the immediate issue while building lasting understanding so I can avoid and resolve similar errors independently in the future.
To troubleshoot this error, follow these steps:
- Check SSL configuration: Ensure that the target's SSL certificate is valid and that it is not using an unsupported Cipher Suite
- Investigate connectivity issues: Look into potential connectivity problems between your application and the external target
- Monitor response times: Check if your application or the external target is experiencing unusual delays that might be contributing to the timeout
