Magnum 1000 Workgroup Hubs Installation and User Guide (04/02)
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there. This happens when a node first sends
Figure 4.2c: External Packet
Forwarded
a packet upon bridge initialization.
Note, therefore, that the address
table learns only internal addresses, i.e.,
those connected via the inside of the local
Magnum 1000, a number typically well
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
External packets
are filtered when
the destination is
NOT IN the
address table.
