# WHATPORT(146)

## NAME

port 146 — ISO-TP0 — ISO transport class 0; the standard TPKT/TP0-over-TCP port is 102, not this one.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA registers 146 as `iso-tp0` (ISO-IP0), part of the family of registrations for running OSI transport over TCP/IP. The one that mattered is port 102, where RFC 1006 puts TPKT and TP0 — the encapsulation that ISO session-layer protocols, and later Siemens S7 industrial gear, actually use. Port 146 carries no deployed implementation. Treat it as a registry artifact and look at 102 if you are chasing real ISO-over-TCP traffic.

## EXPOSURE

**Expose with care.** Nothing standard listens here; if something does, fingerprint it — and check whether the OSI service you actually care about is on 102.

## CHECK

```sh
nc -vz TARGET 146
```

## SEE ALSO

- spec — [RFC 1006 — ISO Transport Service on top of the TCP](https://www.rfc-editor.org/rfc/rfc1006.html) (rfc-editor.org)
- iana — [IANA Service Name and Transport Protocol Port Number Registry](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)

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HTML: <https://whatport.net/146/> · JSON: <https://whatport.net/146.json> · full dataset: <https://whatport.net/ports.json>