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IXP400 Software
Programmer’s Guide IXP400 Software Version 2.0 April 2005
Document Number: 252539, Revision: 007 155
Access-Layer Components:
Ethernet Database (IxEthDB) API 10
This chapter describes the Intel
®
IXP400 Software v2.0 “Ethernet Database API” access-layer
component.
10.1 Overview
To minimize the unnecessary forwarding of frames, an IEEE 802.1d-compliant bridge maintains a
filtering database. IxEthDB provides MAC address-learning and filtering database functionality for
the Ethernet NPE interfaces. IxEthDB also provides the configuration and management of many of
the Ethernet subsystem NPE-based capabilities, such as VLAN/QoS, MAC address firewall, frame
header conversion, etc.
10.2 What’s New
The following changes and enhancements were made to this component in software release 2.0:
• The Ethernet subsystem has been enhanced to include support for the Intel
®
IXP46X Product
Line of Network Processors. This includes supporting the MII interface attached to NPE-A.
All enumerations and definitions reference the Ethernet port on NPE-A as Port 2, except for
the
ixp_ne_dest_port and ixp_ne_src_port IX_OSAL_MBUF fields.
Note: The Intel
®
IXP46X product line processors include an option for a 4-port SMII
capability, using 4 Ethernet coprocessors on NPE-B. In software release 2.0, this
functionality is not supported. Only a single MII interface on NPE-B is supported.
10.3 IxEthDB Functional Behavior
There are two major elements involved in the IxEthDB subsystem: a software database that
executes on the Intel XScale core of the processor, and one or more Network Processing Engines
(NPEs) that are capable of making decisions or performing manipulations on the Ethernet traffic
that they encounter. While the capabilities of the NPEs are determined by the microcode that runs
on them, the specifics related to how the NPE should drop, forward or manipulate the Ethernet
traffic are managed by the IxEthDB component.
IxEthDB handles the configuration of several Ethernet subsystem features:
• MAC Address Learning and Filtering
• Frame Size Filtering
• Source MAC Address Firewall
• 802.1Q VLAN