- 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 146: ISO-IP0
Port 146 is assigned by IANA to iso-tp0 (ISO-IP0).
How iso-tp0 works
Other servicesThe client sends a request to port 146 and the iso-tp0 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
Is port 146 dangerous?
We have no specific security note for port 146. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 146
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| iso-tp0 | 146 | TCP, UDP | ISO-IP0 | - | - |
// source: IANA service name and port number registry
Which program uses port 146, and is it reachable?
Linux
sudo ss -ltnup 'sport = :146' # process listening on 146
sudo lsof -nP -i :146macOS
sudo lsof -nP -i :146
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 146 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 146 netstat -ano | findstr :146
From another machine
nmap -p 146 -sV <host> sudo nmap -sU -p 146 <host> nc -zv <host> 146
Block it in the firewall
sudo ufw deny 146/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 146" -Direction Inbound -LocalPort 146 -Protocol TCP -Action Block # Windows
What is port 146 used for?
Port 146 is assigned by IANA to iso-tp0 (ISO-IP0).
Is port 146 TCP or UDP?
Port 146 is registered for TCP and UDP.
Is it safe to open port 146?
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 146 is open?
On Linux run "ss -ltnup 'sport = :146'", on macOS "lsof -nP -i :146", and on Windows "netstat -ano | findstr :146" to see the local process. From another machine, "nmap -p 146 <host>" shows whether it is reachable.