CyberHunter
// Other services

Port 1685: n2nremote

Port 1685 is assigned by IANA to n2nremote (n2nremote).

1685

How n2nremote works

Other services
client:1685n2nremoteresponse client:1685n2nremoteresponse

The client sends a request to port 1685 and the n2nremote 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 1685 dangerous?

We have no specific security note for port 1685. 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 1685

ServicePortTransportDescriptionReferenceUpdated
n2nremote 1685 TCP, UDP n2nremote - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 1685, and is it reachable?

Linux

sudo ss -ltnup 'sport = :1685'      # process listening on 1685
sudo lsof -nP -i :1685

macOS

sudo lsof -nP -i :1685

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 1685 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 1685
netstat -ano | findstr :1685

From another machine

nmap -p 1685 -sV <host>
sudo nmap -sU -p 1685 <host>
nc -zv <host> 1685

Block it in the firewall

sudo ufw deny 1685/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 1685" -Direction Inbound -LocalPort 1685 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 1685 used for?

Port 1685 is assigned by IANA to n2nremote (n2nremote).

Is port 1685 TCP or UDP?

Port 1685 is registered for TCP and UDP.

Is it safe to open port 1685?

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 1685 is open?

On Linux run "ss -ltnup 'sport = :1685'", on macOS "lsof -nP -i :1685", and on Windows "netstat -ano | findstr :1685" to see the local process. From another machine, "nmap -p 1685 <host>" shows whether it is reachable.

05 Related