User`s guide

5-4
Filters
but it is not a filter. Multicast storm protection is described in
Chapter 3, Configuring Multicast Storm Protection.
5.4 ADDRESS TABLE FILTERS
The simplest type of filters are address table filters. These filters
use the Bridge Address Table to screen local traffic. To make highly
efficient address filtering possible, the ATX address table includes
filter flags. By setting these flags, a system operator can selectively
filter:
• Traffic to and/or from any station (MAC layer address)
• Multicast traffic from any station (MAC layer address)
The capacity of the ATX address table is 8,192 entries expandable
to 16,384. Of these, 200 can be static (manually entered) entries and
a small number of special reserved addresses; the rest are
dynamically learned addresses. Table 5-1 shows what one
dynamically learned entry in the Bridge Address Table would look
like.
Table 5-1. Representation Of Address Table Entry
The key entry in the address table is the MAC address which is
either the Ethernet, Token Ring, or FDDI address. The port entry
indicates the physical port or segment associated with the address.
The segment port number is automatically learned for dynamic
addresses, but may be manually entered if a static address is
desired. The age entry indicates when a frame from the device was
last received by the ATX. The source filter and multicast source
filter entries are flags used solely for filtering; they instruct the ATX
MAC address
Port
(segment)
Age
Source
filter
Multicast
source
filter
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