ProFTPD

A raw TCP probe, not HTTP — address is host or host:port, no scheme. Port defaults to 21 when omitted. Reads the FTP greeting (RFC 959’s 220 reply) every server sends unprompted on connect, and looks for a version inside it.

targets:
  - id: ftp-main
    product: proftpd
    address: ftp.example.com:21

Authentication

None — the greeting is sent before any authentication step.

The out-of-the-box default has no version at all

With no ServerIdent directive configured — the actual default, confirmed live against both a real production host and a fresh instantlinux/proftpd container — the greeting reads "ProFTPD Server (<ServerName>) [<address>]", carrying no version. The version only appears if an admin explicitly configures ServerIdent on "... %{version} ..." — confirmed live too: "ProFTPD 1.3.9c ready at 127.0.0.1". So this probe’s “no version found” case is the common one, not the exception.

Recorded fields

Only version — this probe records no extra fields.

Lifecycle resolver

endoflife:proftpd.