Document TLS-ALPN-01 challenge requirements for reverse proxy (#656)

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shuuri-labs
2026-03-16 15:26:52 +01:00
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commit 8680e5e822
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@@ -422,6 +422,10 @@ If your self-hosted deployment currently uses Nginx, Caddy, or another reverse p
2. Ensure the wildcard DNS record resolves correctly: `dig myapp.proxy.example.com`
3. Check proxy logs for ACME errors: `docker compose logs proxy | grep -i acme`
4. If using `http-01` challenge type, ensure port 80 is also accessible
5. Ensure no geo-blocking is active on your firewall or CDN - Let's Encrypt validates from multiple global locations simultaneously, and blocking non-local IPs will cause validation to fail
6. If you have an additional proxy or load balancer in front of Traefik, verify it supports the `acme-tls/1` ALPN protocol required by the `tls-alpn-01` challenge. Some providers (such as Cloudflare) may not pass through this protocol. If this is an issue, switch to `NB_PROXY_ACME_CHALLENGE_TYPE=http-01`
For a full explanation of TLS-ALPN-01 requirements, see [TLS-ALPN-01 requirements](/manage/reverse-proxy#tls-alpn-01-requirements).
### TLS passthrough not working