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Port 953 (rndc)

IANA assigns port 953 to rndc: BIND9 remote name daemon controller.

Well-known (system) port, 0-1023 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference
rndc TCP BIND9 remote name daemon controller Internet Systems Consortium Inc -

Registry dates for this port: registered 2017-06-08.

Check what is listening on port 953

Linux: is anything listening on TCP 953?
sudo ss -tlnp 'sport = :953'
Linux / macOS: which process owns the port
sudo lsof -nP -i :953
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':953 '
Windows (Command Prompt)
netstat -ano | findstr :953
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 953 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 953
From Windows
Test-NetConnection HOST -Port 953

Block port 953 in the firewall

ufw
sudo ufw deny 953/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 953 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 953 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 953' -Direction Inbound -Protocol TCP -LocalPort 953 -Action Block

Related ports

914rift-lies915rift-ties989FTPS (implicit, data)990FTPS (implicit, control)

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