Owner's Manual

Chapter 5. Configuring Slots and Ports on a Switch | 125
NETGEAR 8800 User Manual
to be aggregated into one logical port, or link aggregation group (LAG). See IEEE 802.3ad for
more information on this feature. The advantages to link aggregation include an increase in
bandwidth and link redundancy.
This section describes the following topics:
• Link Aggregation Overview on page 125
• Dynamic Versus Static Load Sharing on page 126
• Load-Sharing Algorithms on page 126
• LACP on page 127
• Health Check Link Aggregation on page 130
• Guidelines for Load Sharing on page 131
• Configuring Switch Load Sharing on page 132
• Load-Sharing Examples on page 135
• Displaying Switch Load Sharing on page 137
Link Aggregation Overview
Note: All ports in a LAG must be running at the same speed and duplex
setting. Each port can belong to only one LAG.
Load sharing allows the switch to use multiple ports as a single logical port, or LAG. For
example, VLANs see the LAG as a single logical port. And, although you can only reference
the master port of a LAG to a Spanning Tree Domain (STPD), all the ports of the LAG
actually belong to the specified STPD. Most load-sharing algorithms guarantee packet
sequencing between clients.
Link aggregation, or load sharing, is disabled by default.
If a port in a load-sharing group (or LAG) fails, traffic is redistributed to the remaining ports in
the LAG. If the failed port becomes active again, traffic is redistributed to include that port.
Note: Load sharing must be enabled on both ends of the link, or a network
loop may result.
Link aggregation is most useful when:
• The egress bandwidth of traffic exceeds the capacity of a single link.
• Multiple links are used for network resiliency.
In both situations, the aggregation of separate physical links into a single logical link
multiplies total link bandwidth in addition to providing resiliency against individual link failures.