Port 4883 (wmlserver)

IANA assigns port 4883 to wmlserver: Meier-Phelps License Server.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference

wmlserver TCP Meier-Phelps License Server William Phelps -

Registry dates for this port: registered 2010-03-22.

Linux: is anything listening on TCP 4883?

sudo ss -tlnp 'sport = :4883'

Linux / macOS: which process owns the port

sudo lsof -nP -i :4883

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':4883 '

Windows (Command Prompt)

netstat -ano | findstr :4883

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 4883 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 4883

From Windows

Test-NetConnection HOST -Port 4883

ufw

sudo ufw deny 4883/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 4883 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 4883 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 4883' -Direction Inbound -Protocol TCP -LocalPort 4883 -Action Block

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