- 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 4869: Photon Relay Debug
Port 4869 is assigned by IANA to phrelaydbg (Photon Relay Debug).
How phrelaydbg works
Other servicesThe client sends a request to port 4869 and the phrelaydbg 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 4869 dangerous?
We have no specific security note for port 4869. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 4869
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| phrelaydbg | 4869 | TCP, UDP | Photon Relay Debug | - | - |
// source: IANA service name and port number registry
Which program uses port 4869, and is it reachable?
Linux
sudo ss -ltnup 'sport = :4869' # process listening on 4869
sudo lsof -nP -i :4869macOS
sudo lsof -nP -i :4869
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4869 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 4869 netstat -ano | findstr :4869
From another machine
nmap -p 4869 -sV <host> sudo nmap -sU -p 4869 <host> nc -zv <host> 4869
Block it in the firewall
sudo ufw deny 4869/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 4869" -Direction Inbound -LocalPort 4869 -Protocol TCP -Action Block # Windows
What is port 4869 used for?
Port 4869 is assigned by IANA to phrelaydbg (Photon Relay Debug).
Is port 4869 TCP or UDP?
Port 4869 is registered for TCP and UDP.
Is it safe to open port 4869?
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 4869 is open?
On Linux run "ss -ltnup 'sport = :4869'", on macOS "lsof -nP -i :4869", and on Windows "netstat -ano | findstr :4869" to see the local process. From another machine, "nmap -p 4869 <host>" shows whether it is reachable.