User manual

8-14 Packet Filter

Configuring Filters

Once a filter has been added to the NETServer’s list of managed

filters, you can assign it to NETServer:

• Interfaces

• Users

Interface Filters

You can configure interface filters for any NETServer interface.

Interface filters control access to all networks available for both

modem and non-modem interfaces.

You can specify whether a filter applies to packets entering the

interface (input filter), leaving the interface (output filter), and

packets that can initiate a call (call filter). The NETServer

examines the filtering rules to determine whether the interface

accepts or rejects the packet.

Input Filter

If an input filter is configured on an interface, all received

packets are checked against the filtering rules before being

forwarded to another interface.

Output Filters

If an output filter is configured on an interface, all outbound

packets are checked against the filtering rules before exiting the

NETServer.

Call Filters

If a call filter is configured on an interface, all transmitted

packets are checked against the filtering rules. The filtering

rules determine whether the packet can initiate an outgoing call.

Call filters are checked only after the packet has passed the

output filter check. An interface without a call filter configured

will allow all packets to initiate an outgoing call.