Layer 2 Features - Dell PowerConnect 54 Series User Manual

VLAN-aware MAC-based Switching
Packets arriving from an unknown source address are sent to the microprocessor, where the source addresses
are added to the Hardware Table. Packets addressed to or from this address are more efficiently forwarded
using the Hardware Table.
MAC Multicast Support
Multicast service is a limited broadcast service, which allows one-to-many and many-to-many connections
for information distribution. Layer 2 Multicast service is where a single frame is addressed to a specific
Multicast address, from where copies of the frame are transmitted to the relevant ports. IGMP Snooping is
supported, including IGMP Querier which simulates the behavior of a multicast router, allowing snooping of
the layer 2 multicast domain even though there is no multicast router.
For more information, see "Multicast Forwarding Support" on page 328.

Layer 2 Features

IGMP Snooping
Internet Group Membership Protocol (IGMP) Snooping examines IGMP frame contents, when they are
forwarded by the device from work stations to an upstream Multicast router. From the frame, the device
identifies work stations configured for Multicast sessions, and which Multicast routers are sending Multicast
frames.
For more information, see "IGMP Snooping" on page 339.
Port Mirroring
Port mirroring monitors and mirrors network traffic by forwarding copies of incoming and outgoing packets
from a monitored port to a monitoring port. Users specify which target port receives copies of all traffic
passing through a specified source port.
For more information, see "Defining Port Mirroring Sessions" on page 264.
Broadcast Storm Control
Storm Control enables limiting the amount of Multicast and Broadcast frames accepted and forwarded by
the device.
When Layer 2 frames are forwarded, Broadcast and Multicast frames are flooded to all ports on the relevant
VLAN. This occupies bandwidth, and loads all nodes connected on all ports.
For more information, see "Enabling Storm Control" on page 261.
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Introduction