- 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 190: Gateway Access Control Protocol
Port 190 is assigned by IANA to gacp (Gateway Access Control Protocol).
How gacp works
Other servicesThe client sends a request to port 190 and the gacp 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 190 dangerous?
We have no specific security note for port 190. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 190
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| gacp | 190 | TCP, UDP | Gateway Access Control Protocol | - | - |
// source: IANA service name and port number registry
Which program uses port 190, and is it reachable?
Linux
sudo ss -ltnup 'sport = :190' # process listening on 190
sudo lsof -nP -i :190macOS
sudo lsof -nP -i :190
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 190 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 190 netstat -ano | findstr :190
From another machine
nmap -p 190 -sV <host> sudo nmap -sU -p 190 <host> nc -zv <host> 190
Block it in the firewall
sudo ufw deny 190/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 190" -Direction Inbound -LocalPort 190 -Protocol TCP -Action Block # Windows
What is port 190 used for?
Port 190 is assigned by IANA to gacp (Gateway Access Control Protocol).
Is port 190 TCP or UDP?
Port 190 is registered for TCP and UDP.
Is it safe to open port 190?
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 190 is open?
On Linux run "ss -ltnup 'sport = :190'", on macOS "lsof -nP -i :190", and on Windows "netstat -ano | findstr :190" to see the local process. From another machine, "nmap -p 190 <host>" shows whether it is reachable.