- 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 4930: Host-to-host messaging
Port 4930 is assigned by IANA to fmsg (Host-to-host messaging).
4930
How fmsg works
Other servicesThe client sends a request to port 4930 and the fmsg service answers.
- Transport
- TCP
- 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 4930 dangerous?
We have no specific security note for port 4930. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 4930
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| fmsg | 4930 | TCP | Host-to-host messaging | - | 2026-10-15 |
| - | 4930 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 4930, and is it reachable?
Linux
sudo ss -ltnup 'sport = :4930' # process listening on 4930
sudo lsof -nP -i :4930macOS
sudo lsof -nP -i :4930
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4930 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 4930 netstat -ano | findstr :4930
From another machine
nmap -p 4930 -sV <host> nc -zv <host> 4930
Block it in the firewall
sudo ufw deny 4930/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 4930" -Direction Inbound -LocalPort 4930 -Protocol TCP -Action Block # Windows
What is port 4930 used for?
Port 4930 is assigned by IANA to fmsg (Host-to-host messaging).
Is port 4930 TCP or UDP?
Port 4930 is registered for TCP.
Is it safe to open port 4930?
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 4930 is open?
On Linux run "ss -ltnup 'sport = :4930'", on macOS "lsof -nP -i :4930", and on Windows "netstat -ano | findstr :4930" to see the local process. From another machine, "nmap -p 4930 <host>" shows whether it is reachable.
Other other services ports
:4444 Metasploit default / krb524 tcp · udp · high risk :31337 Back Orifice / elite tcp · udp · high risk :1 TCP Port Service Multiplexer tcp · udp :5 Remote Job Entry tcp · udp :9 Discard tcp · udp · sctp · dccp :11 Active Users tcp · udp :17 Quote of the Day tcp · udp :18 Message Send Protocol (historic) tcp · udp