telnet cli-helper.net 80 #웹 사이트와 telnet 통신
Trying 179.61.189.61...
Connected to cli-helper.net.
Escape character is '^]'.
GET / HTTP/1.1 # METHOD 리소스주소 요청
Host: cli-helper.net # HOST 지정
# 전송
HTTP/1.1 400 Bad Request
Server: hcdn
Date: Fri, 22 Dec 2023 15:53:38 GMT
Content-Type: text/html
Content-Length: 247
Connection: close
alt-svc: h3=":443"; ma=86400
x-hcdn-request-id: d3307c90e78cfd45dce5d85d6b134afa-nme-edge2
<html>
<head><title>400 The plain HTTP request was sent to HTTPS port</title></head>
<body>
<center><h1>400 Bad Request</h1></center>
<center>The plain HTTP request was sent to HTTPS port</center>
<hr><center>hcdn</center>
</body>
</html>
Connection closed by foreign host.