ZyXEL Communications ES-4024 Switch User Manual


 
Dimension ES-4024 Ethernet Switch
Link Aggregation 14-1
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 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. Ports should be
physically linked in consecutive order without gaps when forming trunk groups.
Table 14-1 Trunk Groups
TRUNK GROUP BEGINNING PORT PORT RANGE
1 1 1 to 8
2 9 9 to 16
3 17 17 to 24
4 25 25 and 26 (the uplink ports)
5 S1 S1 and S2 (the stacking ports)
14.1.1 Dynamic Link Aggregation
The ES-4024 adheres to the 802.3ad standard for static and dynamic (LACP) port trunking.
The ES-4024 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:
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.
Chapter 14
Link
Aggregation