ZyXEL Communications ZyXEL Dimension ES-3124 - Manual (Page 119)

Dimension ES-3124 Ethernet Switch
Link Aggregation 14-1
Chapter 14
Link Aggregation
This chapter shows you how to logically aggregate physical links to form one logical, higher-bandwidth
link.
14.1 Introduction to Link Aggregation
Link aggregation (trunking) is the grouping of physical ports into one logical higher-capacity link. You may want
to trunk ports if for example, it is cheaper to use multiple lower-speed links than to under-utilize a high-speed, but
more costly, single-port link.
However, the more ports you aggregate then the fewer available ports you have. A link aggregation group is one
logical link containing multiple ports.
The first port must be physically connected when forming a trunk group.
14.1.1 Dynamic Link Aggregation
The ES-3124 adheres to the 802.3ad standard for static and dynamic (LACP) port trunking.
The ES-3124 supports the link aggregation IEEE802.3ad standard. This standard describes the Link Aggregate
Control Protocol (LACP), which is a protocol that dynamically creates and manages trunk groups.
When you enable LACP link aggregation on a port, the port can automatically negotiate with the ports at the
remote end of a link to establish trunk groups. LACP also allows port redundancy, that is, if an operational port
fails, then one of the “standby” ports become operational without user intervention
Please note that:
¾ You must connect all ports point-to-point to the same Ethernet switch and configure the ports for LACP
trunking.
¾ LACP only works on full-duplex links.
¾ All ports in the same trunk group must have the same media type, speed, duplex mode and flow control
settings.
Configure trunk groups or LACP before you connect the Ethernet switch to avoid causing network topology loops.
14.1.2 Link Aggregation ID
LACP aggregation ID consists of the following information: