Apache访问出现501 Method Not Implemented错误解决

loadfile /usr/libxml2.so.2
loadmodule security_module modules/mod_security2.so
loadmodule unique_id_module modules/mod_unique_id.so

<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

$ telnet www.example.com 80
Trying 192.0.32.10...
Connected to www.example.com.
Escape character is '^]'.
OPTIONS / HTTP/1.1

HTTP/1.1 200 OK
Date: Tue, 08 Dec 2009 02:29:38 GMT
Server: Apache/2.2.3 (CentOS)
Allow: GET,HEAD,POST,OPTIONS,TRACE
Content-Type: text/html; charset=UTF-8
Content-Length: 0
Connection: close

Connection closed by foreign host.
$