XG700 User's Guide
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All Rights Reserved, Copyright (C) PFU LIMITED 2005-2006
4.5 Uplink Filter
When an uplink domain is defined, the domain's uplink domain port filters (drops) multicast, broadcast and unlearned (flooding)
unicast frames from non-membership downlink ports. However it does not filter learned unicast frames that are forwarded
based on MAC table.
The uplink filter is useful in configuring large networks with multiple paths, such as a fat tree network, by cascading multiple XG
series switches.
To configure an uplink filter, specify an uplink domain whose membership consists of one or more downlink ports and one or
more uplink ports. For example, in the fat tree network, an uplink domain is configured such that ports connected to switches
are designated as uplink ports, and leaf nodes as downlink ports. The uplink domain will then block multicast, broadcast and
flooding unicast frames to other uplink domains configured within the switch and only distribute traffic from the downlink to the
uplink ports within that domain.
If an uplink filter is specified to have multiple uplink ports, link aggregation and redundancy are provisioned within that domain.
The uplink filter differs from link aggregation in that the uplink ports within the uplink domain can be connected to different
switches or equipment to ensure redundancy within the various uplink ports.