And’ filters, Or’ filters – Compatible Systems 5.4 User Manual

Page 139

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Chapter 8 - IntraGuard Firewall Configuration

133

If more than one interface is designated as an inside or outside interface on a
particular path, those interfaces are considered to be open multiplexed and
traffic will flow freely between them. For example, in the default configura-
tion, both Ethernet 0 and the Bridge interface are inside interfaces on the
Green-Red Path. Traffic between those two interfaces will not be subjected to
firewall screening.

‘AND’ Filters

AND filters allow the device to accomplish packet filtering on packets that
will be forwarded out the specified interface(s). AND filters are typically
used to deny certain packets, so they are checked only for those protocols or
ports which have been permitted by a Security Policy protocol setting, an
Allow Ports/Protocol setting or an OR filter. Any packet not explicitly
allowed by the rule set is dropped. Filters are created using the IP Filter
Editor, described in the IP Filtering section of this manual. Up to four filter
sets may be listed. The filters will be applied in the order listed.

Use the New button to add a named filter to the list or to select a named filter
from a pull-down list.

Use the Delete button to remove a named filter from the list.

Use the Move Up and Move Down buttons to move the filters into the desired
application order.

‘OR’ Filters

“OR” Filters allow the device to accomplish packet filtering on packets that
will be forwarded out the specified interface(s). OR filters are typically used
to permit certain packets, so they are checked only for those protocols or ports
which have been denied by a Security Policy protocol setting or an Allow
Ports/Protocol setting. Any packet not explicitly allowed by the rule set is
dropped. Up to four filter sets may be listed. The filters will be applied in the
order listed. Filters are created using the IP Filter Editor, described in the IP
Filtering section of this manual.

Use the New button to add a named filter to the list or to select a named filter
from a pull-down list.

Use the Delete button to remove a named filter from the list.

Use the Move Up and Move Down buttons to move the filters into the desired
application order.

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