ZyXEL Communications MES-2110 CHAPTER 16

MES-2110 User’s Guide 117
CHAPTER 16
Link Aggregation
16.1 Overview
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
trunk group is one logical link containing multiple ports.
The beginning port of each trunk group must be physically connected to form a
trunk group.
The MES-2110 supports both static and dynamic link aggregation.
Note: In a properly planned network, it is recommended to implement static link
aggregation only. This ensures increased network stability and control over the
trunk groups on your MES-2110.
See Section 16.3 on page 118 for a static port trunking example.
16.2 Dynamic Link Aggregation
The MES-2110 adheres to the IEEE 802.3ad standard for static and dynamic
(LACP) port trunking.
The MES-2110 supports the link aggregation IEEE802.3ad standard. This standard
describes the Link Aggregation 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: