Apache error in fedora7: solution to code 400

An error occurred in apache under fedora7. Solution to code 400: Linux Enterprise Application-Linux server application information. For details, refer to the following section. Problem:
If you enter 127.0.0.1 or the Host IP address in the browser, the following error occurs:
/**********/

Bad Request
Your browser sent a request that this server cocould not understand.

Apache/2.2.0 (Fedora) Server at 127.0.0.1 Port 80

/*********/

If http: // host name/is opened in the browser on the host, the webpage can be opened normally without an error prompt.

View logs:
/**********/
[Mon Aug 27 08:15:56 2007] [error] [client 127.0.0.1] ModSecurity: Access denied with code 400 (phase 1 ). pattern match "^ [\\\\ d \\\\.] + $ "at REQUEST_HEADERS: Host. [id "960017"] [msg "Host header is a numeric IP address"] [severity "CRITICAL"] [hostname "127.0.0.1"] [uri "/"] [unique_id "QrBrQ38AAAEAACZ5GVAAAAAH "]
/******/

Solution:
Edit the/etc/httpd/modsecurity. d/modsecurity_crs_21_protocol_anomalies.conf file.

Comment out this sentence (that is, add "#" in front "#"):
SecRule REQUEST_HEADERS: Host "^ [\ d \.] + $ "" deny, log, auditlog, status: 400, msg: 'host header is a numeric IP address ', severity: '2', id: '123'

Restart the httpd service.
In this way, security vulnerabilities still exist.