421 Misdirected Request

What it means

HTTP 421 Misdirected Request means the request landed on a server that cannot answer for the requested host. It typically arises with HTTP/2 connection reuse: a client reuses a connection for a hostname that the server on the other end is not set up to serve, often because the TLS certificate covers it but the virtual-host configuration does not.

When it happens

It happens when HTTP/2 coalesces requests for several hostnames onto one connection and one of those hosts is not actually served there, or when a load balancer routes a request to a backend that has no configuration for the target domain.

How to fix it

• Have the client retry the request on a fresh connection rather than a reused one.
• Check that every hostname covered by the certificate is also configured as a served virtual host.
• Review load balancer and routing rules so requests reach a backend that can answer for the host.

SEO impact

Negative if it affects real pages. If crawlers receive 421 on a host you want indexed, those pages will not be fetched, so confirm your virtual-host and HTTP/2 setup is consistent.