CyberHunter
// Other services

Port 597: PTC Name Service

Port 597 is assigned by IANA to ptcnameservice (PTC Name Service).

597

How ptcnameservice works

Other services
client:597ptcnameserviceresponse client:597ptcnameserviceresponse

The client sends a request to port 597 and the ptcnameservice 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)
01 Security

Is port 597 dangerous?

We have no specific security note for port 597. 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 597

ServicePortTransportDescriptionReferenceUpdated
ptcnameservice 597 TCP, UDP PTC Name Service - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 597, and is it reachable?

Linux

sudo ss -ltnup 'sport = :597'      # process listening on 597
sudo lsof -nP -i :597

macOS

sudo lsof -nP -i :597

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 597 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 597
netstat -ano | findstr :597

From another machine

nmap -p 597 -sV <host>
sudo nmap -sU -p 597 <host>
nc -zv <host> 597

Block it in the firewall

sudo ufw deny 597/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 597" -Direction Inbound -LocalPort 597 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 597 used for?

Port 597 is assigned by IANA to ptcnameservice (PTC Name Service).

Is port 597 TCP or UDP?

Port 597 is registered for TCP and UDP.

Is it safe to open port 597?

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 597 is open?

On Linux run "ss -ltnup 'sport = :597'", on macOS "lsof -nP -i :597", and on Windows "netstat -ano | findstr :597" to see the local process. From another machine, "nmap -p 597 <host>" shows whether it is reachable.

05 Related