HTTPfy

Port 4930 (fmsg)

IANA assigns port 4930 to fmsg: Host-to-host messaging.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference
fmsg TCP Host-to-host messaging FMSG AI PTY LTD -

Registry dates for this port: registered 2026-10-15.

Check what is listening on port 4930

Linux: is anything listening on TCP 4930?
sudo ss -tlnp 'sport = :4930'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4930
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4930 '
Windows (Command Prompt)
netstat -ano | findstr :4930
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4930 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4930
From Windows
Test-NetConnection HOST -Port 4930

Block port 4930 in the firewall

ufw
sudo ufw deny 4930/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4930 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4930 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4930' -Direction Inbound -Protocol TCP -LocalPort 4930 -Action Block

Related ports

All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.