IANA assigns port 2552 to call-logging: Call Logging.
sudo ss -tlnp 'sport = :2552'sudo ss -ulnp 'sport = :2552'sudo lsof -nP -i :2552sudo netstat -tlnp | grep ':2552 'netstat -ano | findstr :2552Get-NetTCPConnection -LocalPort 2552 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 2552Test-NetConnection HOST -Port 2552nc -vzu -w 5 HOST 2552sudo ufw deny 2552/tcpsudo iptables -A INPUT -p tcp --dport 2552 -j DROPsudo nft add rule inet filter input tcp dport 2552 dropNew-NetFirewallRule -DisplayName 'Block TCP 2552' -Direction Inbound -Protocol TCP -LocalPort 2552 -Action Blocksudo ufw deny 2552/udpsudo iptables -A INPUT -p udp --dport 2552 -j DROPsudo nft add rule inet filter input udp dport 2552 dropNew-NetFirewallRule -DisplayName 'Block UDP 2552' -Direction Inbound -Protocol UDP -LocalPort 2552 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.