GarrettCom 1024 Magnum 1000 Workgroup Hubs, Installation and User Guide 04/02, 2c External Packet

Magnum 1000 Workgroup Hubs	Installation and User Guide (04/02)
there. This happens when a node first sends		Figure 4.2c: External Packet
Forwarded
a packet upon bridge initialization.
Note, therefore, that the address		External packets
table learns only internal addresses, i.e.,
		are filtered when
those connected via the inside of the local		the destination is
		NOT IN the
Magnum 1000, a number typically well		address table.
under the 256 table addresses size. Should
the table become full, the BPM will clear all
entries in the table by reinitializing itself.
When

an external packet’s source address

is in the address table, it is purged. Figure 4.2d: External Packet Filtered

This can occur if a node has physically moved to a different location.

A summary of the filtering, forwarding, and address table

maintenance performed by the BPMs is shown in Table 4.2.

Table 4.2: BPM Functionality

Packet	Source	Destination	Address Table	Filter/Forward
Source	Address	Address	Maintenance	Action
Internal	Not in table	Not in table	Add source to table	Forward
Internal	Not in table	In table	Add source to table	Filter
Internal	In table	Not in table	Nothing	Forward
Internal	In table	In table	Nothing	Filter
External	Not in table	Not in table	Nothing	Filter
External	Not in table	In table	Nothing	Forward
External	In table	Not in table	Purge source from table	Filter
External	In table	In table	Purge source from table	Forward

2.Throughput Increase: By using a BPM to isolate a user group segment having significant local traffic, it is possible to increase overall network throughput. For example, a segment containing a group of workstations and servers may have heavy local traffic, but only a small amount of traffic that is

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