IANA assigns port 2137 to connect: CONNECT.
sudo ss -tlnp 'sport = :2137'sudo ss -ulnp 'sport = :2137'sudo lsof -nP -i :2137sudo netstat -tlnp | grep ':2137 'netstat -ano | findstr :2137Get-NetTCPConnection -LocalPort 2137 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 2137Test-NetConnection HOST -Port 2137nc -vzu -w 5 HOST 2137sudo ufw deny 2137/tcpsudo iptables -A INPUT -p tcp --dport 2137 -j DROPsudo nft add rule inet filter input tcp dport 2137 dropNew-NetFirewallRule -DisplayName 'Block TCP 2137' -Direction Inbound -Protocol TCP -LocalPort 2137 -Action Blocksudo ufw deny 2137/udpsudo iptables -A INPUT -p udp --dport 2137 -j DROPsudo nft add rule inet filter input udp dport 2137 dropNew-NetFirewallRule -DisplayName 'Block UDP 2137' -Direction Inbound -Protocol UDP -LocalPort 2137 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.