Ask about port-based VM settings

For more information about port-based VM settings, see Linux Enterprise Application-Linux server application. It turns out that a port-based virtual host is built on port 80, that is, the specified address mail.xxx.com is opened in the browser to directly access the virtual host. The following is httpd. partial configuration in conf (Environment: CentOS4.7 ):

Listen 80
ServerName G_MY_HOST_NAME: 80
NameVirtualHost *: 80

ServerName mail.xxx.com
DocumentRoot/var/www/extsuite/extmail/html/

ScriptAlias/extmail/cgi // var/www/extsuite/extmail/cgi/
Alias/extmail/var/www/extsuite/extmail/html/

ScriptAlias/extman/cgi // var/www/extsuite/extman/cgi/
Alias/extman/var/www/extsuite/extman/html/

Alias/phpmyadmin/var/www/extsuite/phpmyadmin/
Alias/phpldapadmin/var/www/extsuite/phpldapadmin/htdocs/
# Suexec config
SuexecUserGroup vuser vgroup


Because this is a private web mail system, considering the security, you want to change the port to the following:

Listen 643.
ServerName G_MY_HOST_NAME: 643
Namevirtualhost*: 643

ServerName mail.xxx.com
DocumentRoot/var/www/extsuite/extmail/html/

ScriptAlias/extmail/cgi // var/www/extsuite/extmail/cgi/
Alias/extmail/var/www/extsuite/extmail/html/

ScriptAlias/extman/cgi // var/www/extsuite/extman/cgi/
Alias/extman/var/www/extsuite/extman/html/

Alias/phpmyadmin/var/www/extsuite/phpmyadmin/
Alias/phpldapadmin/var/www/extsuite/phpldapadmin/htdocs/
# Suexec config
SuexecUserGroup vuser vgroup


Restart apache, in the browser input: http://mail.xxx.com: 643 but cannot open the web page, I do not know why, is it related to the configuration to correct the error, please help correct.