Port 9001 Tor ORPort / Supervisor · TCP

What runs on port 9001

Tor's default ORPort (relay-to-relay traffic, with 9030 as the directory port), Supervisor's HTTP interface (supervisorctl over inet_http_server), and the WebSocket listener of several MQTT brokers. On a Tor relay it must be public; on an application server, Supervisor on 9001 with no password is a remote shell.

Software that uses it: Tor (relay ORPort) · Supervisor (inet_http_server) · Mosquitto/EMQX WebSocket listeners · ETCD in some configurations

Should port 9001 be open?

Internet-facing only with authentication and care. It can be exposed when the service behind it is authenticated, rate-limited and kept up to date; most deployments are better off behind a VPN, an allow-list or a reverse proxy.

• Supervisor: keep inet_http_server off or bind it to 127.0.0.1 with a username/password.

Check port 9001

# on the host: is anything listening, and which process?
ss -ltnp 'sport = :9001'
sudo lsof -i :9001

# from another machine: is it reachable?
nc -zv host 9001
nmap -p 9001 host
curl -v telnet://host:9001      # raw TCP connect test, Ctrl-C to leave

A port that answers from the internet when it should not is the finding; nmap from a machine outside your network (or a VPS) is the honest test, because scans from inside the LAN pass the firewall you are trying to verify.

Allow or block port 9001

# ufw (Ubuntu/Debian)
sudo ufw allow from 10.0.0.0/8 to any port 9001 proto tcp
sudo ufw deny 9001/tcp

# nftables
nft add rule inet filter input ip saddr 10.0.0.0/8 tcp dport 9001 accept
nft add rule inet filter input tcp dport 9001 drop

# iptables (legacy)
iptables -A INPUT -p tcp --dport 9001 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 9001 -j DROP

# firewalld
sudo firewall-cmd --permanent --add-rich-rule='rule family=ipv4 source address=10.0.0.0/8 port port=9001 protocol=tcp accept'

Replace 10.0.0.0/8 with the networks that need access. Allowing by source address is the rule that matters; "allow 9001" with no source is just "open".

Related ports

• 9050 Tor SOCKS
• 1883 MQTT — IoT messaging

Part of the port number reference. Ports are 16-bit numbers; see also the subnet calculator and the packet decoder, which shows ports inside TCP and UDP headers.

Questions