> For the complete documentation index, see [llms.txt](https://docs.defguard.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.defguard.net/2.1/support-1/troubleshooting-guides/core/h2-protocol-error-from-reverse-proxy.md). # h2 protocol error from reverse proxy Error message: ``` h2 protocol error: http2 error: stream error received: not a result of an error ``` This error appears when the client maintains a long-lived connection through a reverse proxy (nginx, Caddy, HAProxy, etc.) and the proxy closes the connection due to its idle or keepalive timeout. This is expected behaviour. Every reverse proxy has a maximum time it will keep an idle connection open. Once that threshold is reached, the proxy closes the stream, which surfaces as this h2 error on the client side. Increasing the proxy's keepalive or idle timeout reduces how frequently the error appears, but it will still occur eventually. The client handles reconnection automatically. No action is required on the Defguard side. The errors are benign and can be ignored. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.defguard.net/2.1/support-1/troubleshooting-guides/core/h2-protocol-error-from-reverse-proxy.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.