CyberHunter
Local dataset, no network
// Other services

Port 168: RSVD

Port 168 is assigned by IANA to rsvd (RSVD).

168

How rsvd works

Other services
client:168rsvdresponse client:168rsvdresponse

The client sends a request to port 168 and the rsvd 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 168 dangerous?

We have no specific security note for port 168. 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 168

ServicePortTransportDescriptionReferenceUpdated
rsvd 168 TCP, UDP RSVD - 2008-05-01

// source: IANA service name and port number registry

03 Check it

Which program uses port 168, and is it reachable?

Linux

sudo ss -ltnup 'sport = :168'      # process listening on 168
sudo lsof -nP -i :168

macOS

sudo lsof -nP -i :168

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 168 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 168
netstat -ano | findstr :168

From another machine

nmap -p 168 -sV <host>
sudo nmap -sU -p 168 <host>
nc -zv <host> 168

Block it in the firewall

sudo ufw deny 168/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 168" -Direction Inbound -LocalPort 168 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 168 used for?

Port 168 is assigned by IANA to rsvd (RSVD).

Is port 168 TCP or UDP?

Port 168 is registered for TCP and UDP.

Is it safe to open port 168?

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 168 is open?

On Linux run "ss -ltnup 'sport = :168'", on macOS "lsof -nP -i :168", and on Windows "netstat -ano | findstr :168" to see the local process. From another machine, "nmap -p 168 <host>" shows whether it is reachable.

05 Related

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