Intel IXP400 MAC Filtering, 1.6 802.3x Flow Control, Non-Promiscuous Mode, Address Filtering

Intel® IXP400 Software

Access-Layer Components: Ethernet Access (IxEthAcc) API

This feature is available on a per-port basis and should be set before a port is enabled.

9.6.1.5MAC Filtering

The MAC subcomponent within the Ethernet NPEs is capable of operation in either promiscuous or non-promiscuous mode. An API to control the operation of the MAC is provided.

Warning: Always use the ixEthAcc APIs to Set and Clear Promiscuous Mode. If the MAC Rx control register is modified directly, some flags in the IX_OSAL_MBUF header will not be populated properly.

Promiscuous Mode

All valid Ethernet frames are forwarded to the NPE for receive processing. NPE Learning/Filtering will not function in IxEthDB unless the MACs are configured in promiscuous mode.

Non-Promiscuous Mode

This allows the following frame types to be forwarded to the NPE for receive processing:

•Frame destination MAC address = Provisioned uni-cast MAC address

•Frame destination MAC address = Broadcast address

•Frame destination MAC address = Provisioned multi-cast MAC addresses. The MAC uses a mask and a multicast filter address. Packets where (dstMacAddress & mask) = (mCastfilter & mask) are forwarded to the NPE.

Address Filtering

The following functions are provided to manage the MAC address tables:

•IxEthAccPortMulticastAddressJoinAll() — all multicast frames are forwarded to the application.

•IxEthAccPortMulticastAddressLeaveAll() — Rollback the effects of IxEthAccPortMulticastAddressJoinAll().

•IxEthAccPortMulticastAddressLeave() — Unprovision a new filtering address.

•IxEthAccPortMulticastAddressJoin() — Provision a new filtering address.

•IxEthAccPortPromiscuousModeSet() — All frames are forwarded to the application regardless of the multicast address provisioned.

•IxEthAccPortPromiscuousModeClear() — Frames are forwarded to the application following the multicast address provisioned.

9.6.1.6802.3x Flow Control

The Ethernet coprocessors adhere to the 802.3x flow control behavior requirements. Upon receiving a PAUSE frame, the Ethernet coprocessor will stop transmitting. PAUSE frames will not be forwarded to the NPE or Intel XScale core. There is no software control for this feature.

April 2005	IXP400 Software Version 2.0	Programmer’s Guide
146	Document Number: 252539, Revision: 007