ZyXEL Communications MES3500-24F User Manual

MES3500-24/24F User’s Guide

This chapter shows you how to logically aggregate physical links to form one logical, higher-
bandwidth link.

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 Switch 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 Switch.

See 

 for a static port trunking example.

The Switch adheres to the IEEE 802.3ad standard for static and dynamic (LACP) port trunking.

The Switch 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: 

• You must connect all ports point-to-point to the same Ethernet switch and configure the ports for 

LACP trunking.

• LACP only works on full-duplex links. 
• All ports in the same trunk group must have the same media type, speed, duplex mode and flow 

control settings.