HTTP registry: dns_error

The intermediary encountered a DNS error when trying to find an IP address for the next-hop hostname.

Proxy and gateway values describe processing across trust boundaries where fields, authority, and framing may be transformed. dns_error is registered in HTTP Proxy Error Types. Defining reference: rfc9209.

httpregistryhttp-proxy-statushttp-proxy-error-types

Identifier (http)

dns_error

The intermediary encountered a DNS error when trying to find an IP address for the next-hop hostname.

Strip hop-by-hop data, normalize framing, trust forwarded metadata only from configured proxies, and avoid exposing topology or credentials.

This registry value is currently marked active by IANA. Follow the defining specification before sending, accepting, or proxying it.

IANA registry: http-proxy-status/http-proxy-error-types

Registry reference: rfc9209

Sources

HTTP Proxy Error Types
rfc9209