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Port 6543 (lds-distrib)

IANA assigns port 6543 to lds-distrib: lds_distrib.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
lds-distrib TCP lds_distrib Jack Baker -
lds-distrib UDP lds_distrib Jack Baker -

Registry dates for this port: registered 2003-06.

Check what is listening on port 6543

Linux: is anything listening on TCP 6543?
sudo ss -tlnp 'sport = :6543'
Linux: UDP 6543
sudo ss -ulnp 'sport = :6543'
Linux / macOS: which process owns the port
sudo lsof -nP -i :6543
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':6543 '
Windows (Command Prompt)
netstat -ano | findstr :6543
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 6543 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 6543
From Windows
Test-NetConnection HOST -Port 6543
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 6543

Block port 6543 in the firewall

ufw
sudo ufw deny 6543/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 6543 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 6543 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 6543' -Direction Inbound -Protocol TCP -LocalPort 6543 -Action Block
ufw
sudo ufw deny 6543/udp
iptables
sudo iptables -A INPUT -p udp --dport 6543 -j DROP
nftables
sudo nft add rule inet filter input udp dport 6543 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 6543' -Direction Inbound -Protocol UDP -LocalPort 6543 -Action Block

Related ports

6514Syslog over TLS6515elipse-rec6544lds-dump6547apc-6547

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