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// Other services

Port 693: almanid Connection Endpoint

Port 693 is assigned by IANA to connendp (almanid Connection Endpoint).

693

How connendp works

Other services
client:693connendpresponse client:693connendpresponse

The client sends a request to port 693 and the connendp 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
Well-known (0-1023)
Category
Other services
01 Security

Is port 693 dangerous?

We have no specific security note for port 693. 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 693

ServicePortTransportDescriptionReferenceUpdated
connendp 693 TCP, UDP almanid Connection Endpoint - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 693, and is it reachable?

Linux

sudo ss -ltnup 'sport = :693'      # process listening on 693
sudo lsof -nP -i :693

macOS

sudo lsof -nP -i :693

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 693 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 693
netstat -ano | findstr :693

From another machine

nmap -p 693 -sV <host>
sudo nmap -sU -p 693 <host>
nc -zv <host> 693

Block it in the firewall

sudo ufw deny 693/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 693" -Direction Inbound -LocalPort 693 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 693 used for?

Port 693 is assigned by IANA to connendp (almanid Connection Endpoint).

Is port 693 TCP or UDP?

Port 693 is registered for TCP and UDP.

Is it safe to open port 693?

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 693 is open?

On Linux run "ss -ltnup 'sport = :693'", on macOS "lsof -nP -i :693", and on Windows "netstat -ano | findstr :693" to see the local process. From another machine, "nmap -p 693 <host>" shows whether it is reachable.

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