IANA assigns port 2550 to ads: ADS.
sudo ss -tlnp 'sport = :2550'sudo ss -ulnp 'sport = :2550'sudo lsof -nP -i :2550sudo netstat -tlnp | grep ':2550 'netstat -ano | findstr :2550Get-NetTCPConnection -LocalPort 2550 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 2550Test-NetConnection HOST -Port 2550nc -vzu -w 5 HOST 2550sudo ufw deny 2550/tcpsudo iptables -A INPUT -p tcp --dport 2550 -j DROPsudo nft add rule inet filter input tcp dport 2550 dropNew-NetFirewallRule -DisplayName 'Block TCP 2550' -Direction Inbound -Protocol TCP -LocalPort 2550 -Action Blocksudo ufw deny 2550/udpsudo iptables -A INPUT -p udp --dport 2550 -j DROPsudo nft add rule inet filter input udp dport 2550 dropNew-NetFirewallRule -DisplayName 'Block UDP 2550' -Direction Inbound -Protocol UDP -LocalPort 2550 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.