Multitech ProxyServer MTPSR1-202ST, Руководство пользователя, Страница: 41 / 142

Chapter 4 - ProxyServer Software
41 MTPSR1-202ST
The ProxyServer administrator can set up “filters” on the proxy server for better control. The Filter
option can be used when you want to block all packets originating from a specific destination (called
source address filtering) or all packets heading for a particular destination (called destination address
filtering). Filters can be set to exclude packets of a particular protocol or any particular field in a LAN
packet.
These filters are based on three basic filter types: Internet Sites (IP Address) (both dotted decimal
and Domain Name), Client Workstation (MAC address or IP address), or Application. To install a
filter, you must first choose one of these basic filter types. Refer to the ProxyServer Help for details
on how to configure the Filter option.
For example, in a filter set up by Domain Name, the system administrator could restrict all users at a
particular site from accessing game sites, X-rated sites, etcetera; or, users at a particular MAC
address or IP address could be restricted from using the services of the ProxyServer; or, you could
restrict all users from accessing specific applications (e.g., FTP, chat, etcetera).
Note: The Filter option does not perform content filtering; rather, the system administrator needs to
restrict users from the particular Internet site, client workstation, or application through the Filters
dialog box.
Note: Adding applications may decrease performance speed and increase security risks. Therefore,
you may want to delete unused or rarely used applications.
To further enhance the security of the firewall network, the FTP button on the Proxy Applications
configuration dialog box allows you to change the FTP Control Port and Data Port Numbers. If you
do change these numbers, make certain that you inform users who need to access the FTP server
what the new numbers are. By default, the FTP server’s Control Port Number is 21 and the Data Port
Number is 20.