[herrold@centos-4 ~]$ telnet localhost 631
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
HELO
HTTP/1.0 400 Bad Request
Date: Thu, 07 Sep 2006 20:30:17 GMT
Server: CUPS/1.1
Upgrade: TLS/1.0,HTTP/1.1
Connection: close
Content-Type: text/html
Content-Length: 101

<HTML><HEAD><TITLE>400 Bad Request</TITLE></HEAD><BODY><H1>Bad Request</H1>Bad Request</BODY></HTML>
Connection closed by foreign host.
[herrold@centos-4 ~]$