FTP Reply Codes

FTP 502 — Command not implemented

In FTP Reply Codes, code 502. The official source describes it as “Command not implemented”. Its concrete cause depends on the operation and surrounding message.

Code502
Symbol
Source confidencehigh

Official definition

Command not implemented

In plain language

In FTP Reply Codes, code 502. The official source describes it as “Command not implemented”. Its concrete cause depends on the operation and surrounding message.

Context to inspect

  • The surrounding operation, version and subsystem determine the actual cause.
  • The same numeric value can mean something different in another namespace.

Safe first checks

  1. Confirm which product, protocol or subsystem produced the code.
  2. Read the full surrounding error message and inspect relevant logs.
  3. Compare the code with the linked authoritative documentation before changing configuration.

Important context

The surrounding operation, version and subsystem determine the actual cause.

Authoritative source

RFC 959 — FTP

Related codes