Broadcast Suppression

Introduction

Broadcast Suppression enables a user to set a desired limit of receive broadcast frames per port/per second to be forwarded out the other ports on the module up to the set limit. Any broadcast frames above this speciÞed limit are dropped. In the event that broadcast frames are being suppressed, multicast and unicast frames continue to be switched.

Port Redirect Function

The Port Redirect function, also referred to as ÒPort Mirroring,Ó is a troubleshooting tool used to map trafÞc from a single source port to a destination port within the chassis. This feature allows all packets, including those with errors, to be copied and sent to an analyzer or RMON probe. The analyzer or RMON probe will see the data as if it is directly connected to the LAN segment of the source port.

Flow Control

Flow Control is a method of managing the ßow of frames between two devices. It ensures that a transmitting device does not overwhelm a receiving device with data. This enables the receiving device to communicate with the transmitting device, and to have it pause its transmission while the receiving device processes the frames already received. Flow control can be enabled or disabled on a port-by- port basis. Both devices must support the IEEE 802.3x standard for ßow control to work.

The 9H532-24, 9H533-24, 9H531-24 and 9H539-24 support the following two types of ßow control:

¥frame based 802.3x

¥back pressure

Frame based 802.3x ßow control is supported on all Ethernet ports operating in the full duplex mode.

Back pressure ßow control is supported on all Ethernet ports operating in the standard mode of operation.

802.1p Port Priority

The IEEE 802.1p standard is used to assign a default priority to the frames received without priority information in their tag header, and to map prioritized frames to the appropriate transmit queues.

The default priority-to-queue mappings are shown in Table 1-1.This conÞguration can be changed by the administrator.

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