CyberHunter
// Other services

Port 4685: Autopac Protocol

Port 4685 is assigned by IANA to autopac (Autopac Protocol).

4685

How autopac works

Other services
client:4685autopacresponse client:4685autopacresponse

The client sends a request to port 4685 and the autopac 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)
01 Security

Is port 4685 dangerous?

We have no specific security note for port 4685. Its risk depends on the program actually listening on it. General advice for other services services:

  • 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.
02 Registry

IANA registry entries for port 4685

ServicePortTransportDescriptionReferenceUpdated
autopac 4685 TCP, UDP Autopac Protocol - 2005-08

// source: IANA service name and port number registry

03 Check it

Which program uses port 4685, and is it reachable?

Linux

sudo ss -ltnup 'sport = :4685'      # process listening on 4685
sudo lsof -nP -i :4685

macOS

sudo lsof -nP -i :4685

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 4685 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 4685
netstat -ano | findstr :4685

From another machine

nmap -p 4685 -sV <host>
sudo nmap -sU -p 4685 <host>
nc -zv <host> 4685

Block it in the firewall

sudo ufw deny 4685/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 4685" -Direction Inbound -LocalPort 4685 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 4685 used for?

Port 4685 is assigned by IANA to autopac (Autopac Protocol).

Is port 4685 TCP or UDP?

Port 4685 is registered for TCP and UDP.

Is it safe to open port 4685?

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 4685 is open?

On Linux run "ss -ltnup 'sport = :4685'", on macOS "lsof -nP -i :4685", and on Windows "netstat -ano | findstr :4685" to see the local process. From another machine, "nmap -p 4685 <host>" shows whether it is reachable.

05 Related