CyberHunter
// Email

Port 6785: DGPF Individual Exchange

Port 6785 is assigned by IANA to dgpf-exchg (DGPF Individual Exchange).

6785

How dgpf-exchg works

Email
your servertheir serverdgpf-exchg youthemdgpf-exchg

Mail servers hand messages to each other over port 6785, one hop at a time, until the recipient's server.

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
Email
01 Security

Is port 6785 dangerous?

We have no specific security note for port 6785. Its risk depends on the program actually listening on it. General advice for email services:

  • Require TLS and authenticated submission.
  • Make sure the server is not an open relay.
  • Publish SPF, DKIM and DMARC for the domain.
02 Registry

IANA registry entries for port 6785

ServicePortTransportDescriptionReferenceUpdated
dgpf-exchg 6785 TCP, UDP DGPF Individual Exchange - 2006-04

// source: IANA service name and port number registry

03 Check it

Which program uses port 6785, and is it reachable?

Linux

sudo ss -ltnup 'sport = :6785'      # process listening on 6785
sudo lsof -nP -i :6785

macOS

sudo lsof -nP -i :6785

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 6785 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 6785
netstat -ano | findstr :6785

From another machine

nmap -p 6785 -sV <host>
sudo nmap -sU -p 6785 <host>
nc -zv <host> 6785

Block it in the firewall

sudo ufw deny 6785/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 6785" -Direction Inbound -LocalPort 6785 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 6785 used for?

Port 6785 is assigned by IANA to dgpf-exchg (DGPF Individual Exchange).

Is port 6785 TCP or UDP?

Port 6785 is registered for TCP and UDP.

Is it safe to open port 6785?

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. Require TLS and authenticated submission.

How do I check if port 6785 is open?

On Linux run "ss -ltnup 'sport = :6785'", on macOS "lsof -nP -i :6785", and on Windows "netstat -ano | findstr :6785" to see the local process. From another machine, "nmap -p 6785 <host>" shows whether it is reachable.

05 Related