3Com CoreBuilder 3500, Руководство по внедрению, Страница: 213 / 592

Key Concepts 213
Key Concepts
Before you use packet filters, review the following key concepts and
terms:
■
Standard Filters — Packet filters that are supplied with the
CoreBuilder 3500 that the hardware executes at wire speed. You can
load them from the Administration Console, or select them from the
set of predefined filters with the Filter Builder application. (Filter
Builder is part of the Web Management suite of applications. See
Table 30 later in this chapter.)
One standard hardware filter is supported: the portGroup (rejdiffportgrp)
filter.
■
Custom Filters — Packet filters that are executed in software. You
create custom filters in any of these ways:
■
By writing a filter definition using the filter definition language.
■
By selecting from among the predefined custom filters provided by
the Filter Builder application.
■
By using the Filter Builder’s wizards to construct a new filter. (See
Table 30 later in this chapter.)
■
Predefined filters
— Hardware and software filters that are supplied
with the Filter Builder application. Filter Builder provides one standard
filter that is executed by the hardware; the others are custom filters
that are executed in software. (See Table 30 later in this chapter.)
■
Port Groups — A collection of ports that you can reference in a
packet filter. You create port groups from the Administration Console.
You can specify different filtering rules between various port groups.
Standard Packet
Filters
The CoreBuilder 3500 hardware supports standard packet filters.
Standard filters are implemented in the ASIC hardware to achieve the
wirespeed performance. To load them, use the Administration Console’s
bridge packetfilter create
command.
At present, one standard hardware filter is supported: the portGroup
(rejdiffportgrp) filter.
Standard packet filter support in the hardware is limited to the receive all
and transmit all paths. Hardware filtering on the receive multicast,
transmit multicast, and receive internal paths is not available; therefore, if
you assign a standard filter to one of these paths, the system implements
the filter in the software, which can affect performance.