7/TCP/UDP - Pentesting Echo Service
Basic Information
The Echo Protocol is a diagnostic service that returns received data to its sender. RFC 862 defines both a TCP service and a UDP service on port 7.[1]
Default ports: 7/TCP and 7/UDP
PORT STATE SERVICE
7/udp open echo
7/tcp open echoAn exposed UDP echo service can participate in a denial-of-service loop if it is made to exchange traffic with another UDP character-generating service. CERT’s advisory recommends disabling unnecessary UDP diagnostic services and filtering spoofed traffic.[2]
Contact the UDP Echo Service
nc -uvn <IP> 7
Hello echo # Sent by the client
Hello echo # Returned by the serverShodan
port:7 echo