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// Network services

Port 6489: Service Registry Default Admin Domain

Port 6489 is assigned by IANA to sun-sr-admin (Service Registry Default Admin Domain).

6489

How sun-sr-admin works

Network services
client:6489sun-sr-adminresponse client:6489sun-sr-adminresponse

The 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
01 Security

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:

  • 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.
02 Registry

IANA registry entries for port 6489

ServicePortTransportDescriptionReferenceUpdated
sun-sr-admin 6489 TCP, UDP Service Registry Default Admin Domain - 2006-03

// source: IANA service name and port number registry

03 Check it

Which program uses port 6489, and is it reachable?

Linux

sudo ss -ltnup 'sport = :6489'      # process listening on 6489
sudo lsof -nP -i :6489

macOS

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
04 FAQ
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.

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