Owner's Manual

25
L2 Feature
The L2 Feature tab exhibits complete standard-based Layer 2 switching capabilities, including:
Link Aggregation, 802.1D Spanning Tree Protocol, 802.1w Rapid Spanning Tree Protocol,
802.1s Multiple Spanning Tree Protocol, MAC Address Table, Internet Group Management
Protocol (IGMP) Snooping, Port Mirroring, 802.1ab Link Layer Discovery Protocol (LLDP), and
Multicast Listener Discovery (MLD) snooping. Utilize these features to configure the Switch to
your preferences.
Link Aggregation
A Link Aggregation Group (LAG) optimizes port usage by linking a group of ports together to form
a single, logical, higher-bandwidth link. Aggregating ports multiplies the bandwidth and increases
port flexibility for the Switch. Link Aggregation is most commonly used to link a bandwidth
intensive network device (or devices), such as a server, to the backbone of a network.
The participating ports are called Members of a port trunk group. Since all ports of the trunk
group must be configured to operate in the same manner, the configuration of the one port of the
trunk group is applied to all ports of the trunk group. Thus, you will only need to configure one of
any of the ports in a trunk group. A specific data communication packet will always be
transmitted over the same port in a trunk group. This ensures the delivery of individual frames of
a data communication packet will be received in the correct order. The traffic load of the LAG will
be balanced among the ports according to Aggregate Arithmetic. If the connections of one or
several ports are broken, the traffic of these ports will be transmitted on the normal ports, so as
to guarantee the connection reliability.
When you aggregate ports, the ports and LAG must fulfill the following conditions:
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All ports within a LAG must be the same media/format type.
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A VLAN is not configured on the port.
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The port is not assigned to another LAG.
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The Auto-negotiation mode is not configured on the port.
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The port is in full-duplex mode.
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All ports in the LAG have the same ingress filtering and tagged modes.
•
All ports in the LAG have the same back pressure and flow control modes.
•
All ports in the LAG have the same priority.
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All ports in the LAG have the same transceiver type.
•
Ports can be configured as LACP ports only if the ports are not part of a previously
configured LAG.
LACP is a dynamic protocol which helps to automate the configuration and maintenance of LAG’s.
The main purpose of LACP is to automatically configure individual links to an aggregate bundle,
while adding new links and helping to recover from link failures if the need arises. LACP can
monitor to verify if all the links are connected to the authorized group. LACP is a standard in