Zte OX253P, Руководство пользователя

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Chapter 11 The Firewall Screens
OX253P User ’ s Guide
124
11.4 Technical Reference
The following section contains additional technical information about the OX253P
features described in this chapter.
11.4.1 Stateful Inspection Firewall.
Stateful inspection firewalls restrict access by screening data packets against
defined access rules. They make access control decisions based on IP address and
protocol. They also "inspect" the session data to assure the integrity of the
connection and to adapt to dynamic protocols. These firewalls generally provide
the best speed and transparency; however, they may lack the granular application
level access control or caching that some proxies support. Firewalls, of one type or
another, have become an integral part of standard security solutions for
enterprises.
Available
Services This is a list of pre-defined services (destination ports) you may prohibit
your LAN computers from using. Select the port you want to block, and
click Add to add the port to the Blocked Services field.
A custom port is a service that is not available in the pre-defined
Available Services list. You must define it using the Type and Port
Number fields.
Blocked
Services This is a list of services (ports) that are inaccessible to computers on
your LAN when service blocking is effective. To remove a service from
this list, select the service, and click
Delete .
Type Select TCP or UDP , based on which one the custom port uses.
Port Number Enter the range of port numbers that defines the service. For example,
suppose you want to define the Gnutella service. Select
TCP type and
enter a port range of 6345-6349 .
Add Click this to add the selected service in Available Services to the
Blocked Services list.
Delete Select a service in the Blocked Services , and click this to remove the
service from the list.
Clear All Click this to remove all the services in the Blocked Services list.
Schedule to Block
Day to Block
Select which days of the week you want the service blocking to be
effective.
Time of Day to
Block Select what time each day you want service blocking to be effective.
Enter times in 24-hour format; for example, 3:00pm should be entered
as 15:00.
Apply Click to save your changes.
Reset Click to restore your previously saved settings.
Table 46 TOOLS > Firewall > Services (continued)
LABEL DESCRIPTION