- 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 3558: MCP user port
Port 3558 is assigned by IANA to mcp-port (MCP user port).
How mcp-port works
Other servicesThe client sends a request to port 3558 and the mcp-port 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 3558 dangerous?
We have no specific security note for port 3558. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 3558
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| mcp-port | 3558 | TCP, UDP | MCP user port | - | 2002-07 |
// source: IANA service name and port number registry
Which program uses port 3558, and is it reachable?
Linux
sudo ss -ltnup 'sport = :3558' # process listening on 3558
sudo lsof -nP -i :3558macOS
sudo lsof -nP -i :3558
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3558 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 3558 netstat -ano | findstr :3558
From another machine
nmap -p 3558 -sV <host> sudo nmap -sU -p 3558 <host> nc -zv <host> 3558
Block it in the firewall
sudo ufw deny 3558/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 3558" -Direction Inbound -LocalPort 3558 -Protocol TCP -Action Block # Windows
What is port 3558 used for?
Port 3558 is assigned by IANA to mcp-port (MCP user port).
Is port 3558 TCP or UDP?
Port 3558 is registered for TCP and UDP.
Is it safe to open port 3558?
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 3558 is open?
On Linux run "ss -ltnup 'sport = :3558'", on macOS "lsof -nP -i :3558", and on Windows "netstat -ano | findstr :3558" to see the local process. From another machine, "nmap -p 3558 <host>" shows whether it is reachable.