- 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.
Port 1764: cft-3
Port 1764 is assigned by IANA to cft-3 (cft-3).
How cft-3 works
Other servicesThe client sends a request to port 1764 and the cft-3 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
Is port 1764 dangerous?
We have no specific security note for port 1764. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 1764
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| cft-3 | 1764 | TCP, UDP | cft-3 | - | - |
// source: IANA service name and port number registry
Which program uses port 1764, and is it reachable?
Linux
sudo ss -ltnup 'sport = :1764' # process listening on 1764
sudo lsof -nP -i :1764macOS
sudo lsof -nP -i :1764
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1764 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 1764 netstat -ano | findstr :1764
From another machine
nmap -p 1764 -sV <host> sudo nmap -sU -p 1764 <host> nc -zv <host> 1764
Block it in the firewall
sudo ufw deny 1764/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 1764" -Direction Inbound -LocalPort 1764 -Protocol TCP -Action Block # Windows
What is port 1764 used for?
Port 1764 is assigned by IANA to cft-3 (cft-3).
Is port 1764 TCP or UDP?
Port 1764 is registered for TCP and UDP.
Is it safe to open port 1764?
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 1764 is open?
On Linux run "ss -ltnup 'sport = :1764'", on macOS "lsof -nP -i :1764", and on Windows "netstat -ano | findstr :1764" to see the local process. From another machine, "nmap -p 1764 <host>" shows whether it is reachable.