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Port 4999 (hfcs-manager)

IANA assigns port 4999 to hfcs-manager: HFSQL Client/Server Database Engine Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
hfcs-manager TCP HFSQL Client/Server Database Engine Manager PC SOFT -
hfcs-manager UDP HFSQL Client/Server Database Engine Manager PC SOFT -

Registry dates for this port: registered 2006-03-02, last modified 2014-02-02.

Check what is listening on port 4999

Linux: is anything listening on TCP 4999?
sudo ss -tlnp 'sport = :4999'
Linux: UDP 4999
sudo ss -ulnp 'sport = :4999'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4999
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4999 '
Windows (Command Prompt)
netstat -ano | findstr :4999
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4999 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4999
From Windows
Test-NetConnection HOST -Port 4999
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4999

Block port 4999 in the firewall

ufw
sudo ufw deny 4999/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4999 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4999 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4999' -Direction Inbound -Protocol TCP -LocalPort 4999 -Action Block
ufw
sudo ufw deny 4999/udp
iptables
sudo iptables -A INPUT -p udp --dport 4999 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4999 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4999' -Direction Inbound -Protocol UDP -LocalPort 4999 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.