- Require authentication on cameras and media servers.
- Keep IP cameras and recorders off the Internet; use a VPN for remote viewing.
- Update device firmware.
Port 201: AppleTalk Routing Maintenance
Port 201 is assigned by IANA to at-rtmp (AppleTalk Routing Maintenance).
201
How at-rtmp works
Media & streamingThe device streams video frames over port 201, continuously, as they are captured.
- Transport
- TCP · UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Well-known (0-1023)
- Category
- Media & streaming
Is port 201 dangerous?
We have no specific security note for port 201. Its risk depends on the program actually listening on it. General advice for media & streaming services:
IANA registry entries for port 201
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| at-rtmp | 201 | TCP, UDP | AppleTalk Routing Maintenance | - | - |
// source: IANA service name and port number registry
Which program uses port 201, and is it reachable?
Linux
sudo ss -ltnup 'sport = :201' # process listening on 201
sudo lsof -nP -i :201macOS
sudo lsof -nP -i :201
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 201 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 201 netstat -ano | findstr :201
From another machine
nmap -p 201 -sV <host> sudo nmap -sU -p 201 <host> nc -zv <host> 201
Block it in the firewall
sudo ufw deny 201/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 201" -Direction Inbound -LocalPort 201 -Protocol TCP -Action Block # Windows
What is port 201 used for?
Port 201 is assigned by IANA to at-rtmp (AppleTalk Routing Maintenance).
Is port 201 TCP or UDP?
Port 201 is registered for TCP and UDP.
Is it safe to open port 201?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Require authentication on cameras and media servers.
How do I check if port 201 is open?
On Linux run "ss -ltnup 'sport = :201'", on macOS "lsof -nP -i :201", and on Windows "netstat -ano | findstr :201" to see the local process. From another machine, "nmap -p 201 <host>" shows whether it is reachable.