- Close the port if nothing on the host needs it.
- Identify the process that listens on it (commands below) before opening it in a firewall.
- Expose a service only to the networks that use it.
Port 3969: Landmark Messages
Port 3969 is assigned by IANA to landmarks (Landmark Messages).
How landmarks works
Other servicesThe client sends a request to port 3969 and the landmarks service answers.
- Transport
- TCP · UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Other services
Is port 3969 dangerous?
We have no specific security note for port 3969. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 3969
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| landmarks | 3969 | TCP, UDP | Landmark Messages | - | 2005-08 |
// source: IANA service name and port number registry
Which program uses port 3969, and is it reachable?
Linux
sudo ss -ltnup 'sport = :3969' # process listening on 3969
sudo lsof -nP -i :3969macOS
sudo lsof -nP -i :3969
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3969 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 3969 netstat -ano | findstr :3969
From another machine
nmap -p 3969 -sV <host> sudo nmap -sU -p 3969 <host> nc -zv <host> 3969
Block it in the firewall
sudo ufw deny 3969/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 3969" -Direction Inbound -LocalPort 3969 -Protocol TCP -Action Block # Windows
What is port 3969 used for?
Port 3969 is assigned by IANA to landmarks (Landmark Messages).
Is port 3969 TCP or UDP?
Port 3969 is registered for TCP and UDP.
Is it safe to open port 3969?
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. Close the port if nothing on the host needs it.
How do I check if port 3969 is open?
On Linux run "ss -ltnup 'sport = :3969'", on macOS "lsof -nP -i :3969", and on Windows "netstat -ano | findstr :3969" to see the local process. From another machine, "nmap -p 3969 <host>" shows whether it is reachable.