Dell PowerConnect M6220, User Configuration Manual

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Switch Features
Protected Ports (Private VLAN Edge)
Private VLAN Edge (PVE) ports are a Layer 2 security feature that provides
port-based security between ports that are members of the same VLAN. It is
an extension of the common VLAN. Traffic from protected ports is sent only
to the uplink ports and cannot be sent to other ports within the VLAN.
For information about configuring IPSG, see "Configuring Port-Based Traffic
Control" on page 687.
Switching Features
Flow Control Support (IEEE 802.3x)
Flow control enables lower speed switches to communicate with higher speed
switches by requesting that the higher speed switch refrains from sending
packets. Transmissions are temporarily halted to prevent buffer overflows.
For information about configuring flow control, see "Configuring Port-Based
Traffic Control" on page 687.
Head of Line Blocking Prevention
Head of Line (HOL) blocking prevention prevents traffic delays and frame
loss caused by traffic competing for the same egress port resources. HOL
blocking queues packets, and the packets at the head of the queue are
forwarded before packets at the end of the queue.
Alternate Store and Forward (ASF)
The Alternate Store and Forward (ASF) feature reduces latency for large
packets. When ASF is enabled, the memory management unit (MMU) can
forward a packet to the egress port before it has been entirely received on the
Cell Buffer Pool (CBP) memory.
AFS, which is also known as cut-through mode, is configurable through the
command-line interface. For information about how to configure the AFS
feature, see the
CLI Reference Guide
available at support.dell.com/manuals .