IANA assigns port 1540 to rds.
sudo ss -tlnp 'sport = :1540'sudo ss -ulnp 'sport = :1540'sudo lsof -nP -i :1540sudo netstat -tlnp | grep ':1540 'netstat -ano | findstr :1540Get-NetTCPConnection -LocalPort 1540 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 1540Test-NetConnection HOST -Port 1540nc -vzu -w 5 HOST 1540sudo ufw deny 1540/tcpsudo iptables -A INPUT -p tcp --dport 1540 -j DROPsudo nft add rule inet filter input tcp dport 1540 dropNew-NetFirewallRule -DisplayName 'Block TCP 1540' -Direction Inbound -Protocol TCP -LocalPort 1540 -Action Blocksudo ufw deny 1540/udpsudo iptables -A INPUT -p udp --dport 1540 -j DROPsudo nft add rule inet filter input udp dport 1540 dropNew-NetFirewallRule -DisplayName 'Block UDP 1540' -Direction Inbound -Protocol UDP -LocalPort 1540 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.