Internetwork zone name filtering with selective placebo zone name substitution in a response to a request for zone name information

摘要

A zone filtering method and apparatus, finding particular utility in an AppleTalk (trademark of Apple Computing, Inc.) internetwork, is disclosed. A network manager is able to hide zones and respective Network Visible Entities (NVE's) from nodes (routers and workstations) on branches of the AppleTalk internetwork through the use of zone filters. These nodes are thus unable to initiate communication with NVE's within the hidden zones. A zone filter is a list of zone names and an indication of whether access to the listed zones is permitted or denied. The port to which a zone filter is attached identifies which branch of the AppleTalk internetwork the zone filter applies to. A router according to the invention is capable of recognizing specific datagrams to which the zone filter is applied.