- Answer only the networks that need the service (no open resolvers, relays or reflectors).
- UDP services can be abused for DDoS amplification: rate-limit or block them at the edge.
- Disable legacy test services that have no use in production.
Port 6489: Service Registry Default Admin Domain
Port 6489 is assigned by IANA to sun-sr-admin (Service Registry Default Admin Domain).
How sun-sr-admin works
Network servicesThe client sends a request to port 6489 and the sun-sr-admin 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
- Network services
Is port 6489 dangerous?
We have no specific security note for port 6489. Its risk depends on the program actually listening on it. General advice for network services services:
IANA registry entries for port 6489
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| sun-sr-admin | 6489 | TCP, UDP | Service Registry Default Admin Domain | - | 2006-03 |
// source: IANA service name and port number registry
Which program uses port 6489, and is it reachable?
Linux
sudo ss -ltnup 'sport = :6489' # process listening on 6489
sudo lsof -nP -i :6489macOS
sudo lsof -nP -i :6489
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 6489 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 6489 netstat -ano | findstr :6489
From another machine
nmap -p 6489 -sV <host> sudo nmap -sU -p 6489 <host> nc -zv <host> 6489
Block it in the firewall
sudo ufw deny 6489/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 6489" -Direction Inbound -LocalPort 6489 -Protocol TCP -Action Block # Windows
What is port 6489 used for?
Port 6489 is assigned by IANA to sun-sr-admin (Service Registry Default Admin Domain).
Is port 6489 TCP or UDP?
Port 6489 is registered for TCP and UDP.
Is it safe to open port 6489?
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. Answer only the networks that need the service (no open resolvers, relays or reflectors).
How do I check if port 6489 is open?
On Linux run "ss -ltnup 'sport = :6489'", on macOS "lsof -nP -i :6489", and on Windows "netstat -ano | findstr :6489" to see the local process. From another machine, "nmap -p 6489 <host>" shows whether it is reachable.