Compatible Systems 5.4 manual AppleTalk Packet Filter Rules, AppleTalk Filtering

212 Chapter 13 - AppleTalk Filtering

•The Rename button lets you rename the selected set of filter rules.

•The Import button lets you import a previously exported set of filter rules, or a text file in which you have stored filter rules. A file dialog will pop up to ask you to locate an import file.

•The Export button lets you export a set of filter rules to disk. A dialog will pop up to ask you to name the export file.

AppleTalk Packet Filter Rules

The AppleTalk filter editor window allows a set of AppleTalk filtering rules to be defined, edited and identified with a specific name.

Once a set of rules is defined and named, those rules may be linked to several different AppleTalk filter interpreters to accomplish different types of filtering.

Each interpreter understands and uses a subset of the complete AppleTalk rules. The interpreters available are: general packet filtering, get-zone-list filtering and route (RTMP) filtering. Each is described below.

The interpreters will not reorder the rules as they are specified. They will be applied sequentially from the first rule through the last. Any filtered informa- tion not specifically allowed by the set of rules will be dropped silently. If that information is to be allowed, a final permit rule must be specified:

permit

There is an interaction between the packet filtering interpreter and the other interpreters. The packet filter interpreter will be applied to incoming packets before the other interpreters, and it will be applied to outgoing packets after the other interpreters. For example, a received get-zone-list request may be filtered by an input packet filter before it arrives at the get-zone-list inter- preter and the reply may also be filtered again by an outgoing packet filter.

Rules that have been specified using CompatiView may be edited or exam- ined through the command line interface. Likewise, rules defined through the command line interface may be edited through CompatiView. When the rules are downloaded into the device from CompatiView, they will be encrypted.

General Packet Filtering

This interpreter allows packets being forwarded by the device to be filtered on the input and output side of an interface. The only rules used in this inter- preter are the type, srcnet, dstnet, srcnode, dstnode, srcskt and dstskt for