3Com 3CRWE554G72 Network Card User Manual


 
68 CHAPTER 5: GATEWAY CONFIGURATION
To use access control for all computers:
1 Click PCs access authorized services only.
2 Select All PCs to setup the access rights for all computers connected to
the Gateway.
3 Select authorized services by clicking in the appropriate check box(es)
(Figure 52
).
Figure 52 All PCs Setup Screen
In addition to the four authorized services listed, you can choose to allow
or block access to other services. You can either:
Allow all other services with exceptions, or
Block all other services with exceptions
4 To do this, select Allow or Block from the drop down menu and enter the
exceptions into the text box.
The port numbers are specified using a comma-separated list, with
hyphens to denote port number ranges. So for example, entering 2, 3,
5-7 would cause ports 2, 3, 5, 6, and 7 to be activated.
For example, to block access to all services except Web (80) and a service
that uses ports 2,3,5,6 and 7:
1. Tick the Web(80) check box.
2. Select ‘Block’ all other services.
3. Enter ‘2, 3, 5-7’ in the ‘except (specify ports) box. See Figure 53
.