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// Other services

Port 1728: TELINDUS

Port 1728 is assigned by IANA to telindus (TELINDUS).

1728

How telindus works

Other services
client:1728telindusresponse client:1728telindusresponse

The client sends a request to port 1728 and the telindus 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
Other services
01 Security

Is port 1728 dangerous?

We have no specific security note for port 1728. 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 1728

ServicePortTransportDescriptionReferenceUpdated
telindus 1728 TCP, UDP TELINDUS - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 1728, and is it reachable?

Linux

sudo ss -ltnup 'sport = :1728'      # process listening on 1728
sudo lsof -nP -i :1728

macOS

sudo lsof -nP -i :1728

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 1728 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 1728
netstat -ano | findstr :1728

From another machine

nmap -p 1728 -sV <host>
sudo nmap -sU -p 1728 <host>
nc -zv <host> 1728

Block it in the firewall

sudo ufw deny 1728/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 1728" -Direction Inbound -LocalPort 1728 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 1728 used for?

Port 1728 is assigned by IANA to telindus (TELINDUS).

Is port 1728 TCP or UDP?

Port 1728 is registered for TCP and UDP.

Is it safe to open port 1728?

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 1728 is open?

On Linux run "ss -ltnup 'sport = :1728'", on macOS "lsof -nP -i :1728", and on Windows "netstat -ano | findstr :1728" to see the local process. From another machine, "nmap -p 1728 <host>" shows whether it is reachable.

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