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421 Misdirected Request

The request reached a server that cannot answer for this hostname

Seen in Browsers, Apache, nginx, CDNs (HTTP/2)

The server is not configured to answer for the hostname on this connection, usually after HTTP/2 reused a connection opened for another name.

Common causes

  • HTTP/2 connection reuse: a certificate covers several hostnames, but they are served by different servers or virtual hosts.
  • The TLS SNI name differs from the Host header, which Apache rejects with 421.
  • A reverse proxy connecting to an HTTPS upstream without sending SNI.

How to fix it

  1. Serve every hostname on a shared certificate from the same server, or use separate certificates per server.
  2. Make sure clients and proxies send the same name in SNI and Host.
  3. In nginx proxying to HTTPS, set proxy_ssl_server_name on;
Check which names the certificate covers

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Related errors

All 51 HTTP & CDN errors