# WHATPORT(9040)

## NAME

port 9040 — Tor TransPort (convention) — The number Tor transparent-proxy setups conventionally use for TransPort — not an IANA assignment and not a Tor default.

Protocol: TCP  
IANA registry

## DESCRIPTION

Tor's TransPort option accepts TCP connections that a firewall has transparently redirected, so traffic gets torified without the application knowing about SOCKS. Tor ships it disabled (the default is 0) and does not pick a port for you; 9040 is simply the number that torrc examples and Tor-routing gateway configurations settled on, which is why iptables/pf rules everywhere redirect to it. IANA lists 9027–9049 as Unassigned. A listener on 9040 means a Tor transparent proxy is configured on that host or gateway.

## EXPOSURE

**Do not expose.** A reachable TransPort is an open proxy into the Tor network for anyone who can send it a redirected connection; bind it to the internal interface it is meant to serve.

## CHECK

```sh
sudo lsof -nP -iTCP:9040 -sTCP:LISTEN
```

## SEE ALSO

- docs — [tor(1) manual — TransPort](https://manpages.debian.org/unstable/tor/tor.1.en.html) (manpages.debian.org)
- iana — [IANA Service Name and Transport Protocol Port Number Registry — 9040](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=9040) (iana.org)

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HTML: <https://whatport.net/9040/> · JSON: <https://whatport.net/9040.json> · full dataset: <https://whatport.net/ports.json>